Patterns of Eye Movements during Parallel and Serial Visual Search Tasks

By Williams, Diane E.; Reingold, Eyal M. et al. | Canadian Journal of Experimental Psychology, June 1997 | Go to article overview

Patterns of Eye Movements during Parallel and Serial Visual Search Tasks


Williams, Diane E., Reingold, Eyal M., Moscovitch, Morris, Behrmann, Marlene, Canadian Journal of Experimental Psychology


Abstract Eye movements were monitored while subjects performed parallel and serial search tasks. In Experiment la, subjects searched for an "O" among "X"s (parallel condition) and for a "T" among "L"s (serial condition). In the parallel condition of Experiment lb, ""Symbol not transcribed"" was the target and ""Symbol not transcribed""s were distractors; in the serial condition, these stimuli switched roles. Displays contained 1, 12, or 24 stimuli, with both target-present and target-absent trials. RT and eye-movement measures (number of fixations, saccadic error, and latency to move) indicated that search efficiency was greatest in the parallel conditions, followed by the serial condition of Experiment 1a and, finally, by the serial condition of Experiment 1b. This suggests that eye movements are correlated with the attentional processes underlying visual search. How are we able to visually search through our complex environment to find a particular item that we need or want? For example, how are we able to find a pen lying amid papers and books on a cluttered desk? Furthermore, while conducting this search, how do we know that a particular feature in the visual array (e.g., "redness") belongs to one object (e.g., the pen) and not to another (e.g., a book)? Studies attempting to address such questions have made extensive use of the visual search task. In this paradigm, subjects are asked to search stimulus displays for a target among distractors. Typically, both display size (i.e., number of stimuli) and trial type (target present vs. target absent) vary across trials. A target stimulus in a visual search task may be defined either by a distinct feature (feature search task) or by a particular combination or conjunction of features (conjunction search task). For example, in a feature search task, subjects might be asked to look for a red "O" among blue and green "O"s. Here, the target's colour is a unique feature which distinguishes it from the distractors. In a conjunction search task, the target stimulus might be the same red "O," but this time, the distractors could be blue "O"s and red "X"s. In this case, each distractor shares at least one feature with the target, such that the target can only be defined by a specific conjunction of colour and shape. In feature search tasks, the target stimulus is typically found quickly and easily; it seems to "pop out" from the background of distractor stimuli. As a result, the number of distractors in the visual array has little effect on subjects' search latencies. In a conjunction search task, on the other hand, average response time usually increases as a linear function of display size. This increase is more pronounced on negative than on positive trials. In fact, the ratio of the slope on negative trials to that on positive trials is roughly 2:1 (Treisman & Gelade, 1980; Wolfe, Cave, & Franzel, 1989). The feature integration theory of attention was developed by Treisman and her colleagues (e.g., Treisman, 1988; Treisman & Gelade, 1980; Treisman & Gormican, 1988; Treisman, Sykes, & Gelade, 1977) to account for such findings. This theory proposes that features are processed automatically and in parallel. Thus, in a feature search task, response times show little effect of display size because the feature characterizing the target stimulus is detected preattentively and then "calls" attention to the position of the target stimulus in the visual field (Treisman & Gormican, 1988). In contrast, the conjunction of features is thought to require focal attention; as a consequence, stimuli are processed serially in a conjunction search task. To perform such a task, the "spotlight" of attention must be focused on each stimulus in turn, allowing its features to be conjoined to form a unitary object. This process continues until the target stimulus is identified or until the subject, having searched the entire array, decides that it is absent (Treisman & Gelade, 1980; Treisman & Gormican, 1988). …

The rest of this article is only available to active members of Questia

Already a member? Log in now.

Notes for this article

Add a new note
If you are trying to select text to create highlights or citations, remember that you must now click or tap on the first word, and then click or tap on the last word.
One moment ...
Default project is now your active project.
Project items
Notes
Cite this article

Cited article

Style
Citations are available only to our active members.
Buy instant access to cite pages or passages in MLA 8, MLA 7, APA and Chicago citation styles.

(Einhorn, 1992, p. 25)

(Einhorn 25)

(Einhorn 25)

1. Lois J. Einhorn, Abraham Lincoln, the Orator: Penetrating the Lincoln Legend (Westport, CT: Greenwood Press, 1992), 25, http://www.questia.com/read/27419298.

Note: primary sources have slightly different requirements for citation. Please see these guidelines for more information.

Cited article

Patterns of Eye Movements during Parallel and Serial Visual Search Tasks
Settings

Settings

Typeface
Text size Smaller Larger Reset View mode
Search within

Search within this article

Look up

Look up a word

  • Dictionary
  • Thesaurus
Please submit a word or phrase above.
Print this page

Print this page

Why can't I print more than one page at a time?

Help
Full screen
Items saved from this article
  • Highlights & Notes
  • Citations
Some of your highlights are legacy items.

Highlights saved before July 30, 2012 will not be displayed on their respective source pages.

You can easily re-create the highlights by opening the book page or article, selecting the text, and clicking “Highlight.”

matching results for page

    Questia reader help

    How to highlight and cite specific passages

    1. Click or tap the first word you want to select.
    2. Click or tap the last word you want to select, and you’ll see everything in between get selected.
    3. You’ll then get a menu of options like creating a highlight or a citation from that passage of text.

    OK, got it!

    Cited passage

    Style
    Citations are available only to our active members.
    Buy instant access to cite pages or passages in MLA 8, MLA 7, APA and Chicago citation styles.

    "Portraying himself as an honest, ordinary person helped Lincoln identify with his audiences." (Einhorn, 1992, p. 25).

    "Portraying himself as an honest, ordinary person helped Lincoln identify with his audiences." (Einhorn 25)

    "Portraying himself as an honest, ordinary person helped Lincoln identify with his audiences." (Einhorn 25)

    "Portraying himself as an honest, ordinary person helped Lincoln identify with his audiences."1

    1. Lois J. Einhorn, Abraham Lincoln, the Orator: Penetrating the Lincoln Legend (Westport, CT: Greenwood Press, 1992), 25, http://www.questia.com/read/27419298.

    Cited passage

    Thanks for trying Questia!

    Please continue trying out our research tools, but please note, full functionality is available only to our active members.

    Your work will be lost once you leave this Web page.

    Buy instant access to save your work.

    Already a member? Log in now.

    Search by... Author
    Show... All Results Primary Sources Peer-reviewed

    Oops!

    An unknown error has occurred. Please click the button below to reload the page. If the problem persists, please try again in a little while.