Assumptions in cognitive psychology Mental processes mental structures mental representations

Mental processes Series of mental processing steps when carrying out a task notice that the light is red (perception) slow down and stop (look up in memory) press the brake pedal (response execution) your mental behavior is broken down into processing steps

Mental structures E.g., short-term memory, long-term memory carry out processing steps using these structures e.g., put information into STM (example process)

Mental representations Form or shape of your understandings e.g., your understanding of how a university works influence your behavior stored in your long-term memory

Research method Need to measure mental processes, mental structures, and mental representations cognitive psychology has specific techniques for measuring these things key measures are reaction time (RT), accuracy

Reaction Time How long to perform a task measure from start -- time information first given measure to the end -- time of the final response in the task

Units of RT Millisecond = 1/1000 second (ms or msec) (e.g., how long to recognize an object) seconds (e.g., name one professor from two terms ago; a memory task) minutes (e.g., taking an exam)

Accuracy How well you perform a task usually, what percentage of a task did you do right (e.g., 85% on an exam) or, proportion correct (PC) 0.85 error rate = how poorly a task is performed (e.g., driving errors when using cell phone) error rate --> a proportion or percentage

COFFEE IS THIS A WORD? TYPICAL SPEED = 500 MS

What does the RT tell us? Speed of response tells us that our words in our head (mental dictionary) must be organized in some very good fashion RT measures the organization of our mental dictionary

Example of accuracy as measure Give a list of words to memorize (say about 20 words, 2 seconds per word) typical results: words at beginning of list remembered well (high accuracy) words in the middle are remembered horribly (low accuracy) words at the end are remembered well

explanation Beginning words benefit because there are so few at the beginning and you have time to work on them and get them into memory middle words add too much for you to process at once, so performance declines last words benefit from being in short-term memory