The overall goal of this experiment is to investigate the frequency effect of Chinese characters and words by combining the lexical decision task and the naming task. This method can help answer key questions in the psycholinguistic field, such as when the retrieval of phonology occurs in the Chinese recognition process. The main advantage of this procedure is now researchers can obtain a more complete and precise picture of character or word recognition by comparing results from two tasks.
Visual demonstration of this method is critical because constructing the pseudo-characters is difficult to learn due to the structural complexity of the Chinese character. Prior to the experiment, recruit sufficient right-handed native Chinese speakers with normal or corrected to normal vision, equally split by gender, who are fluent in listening, speaking, reading, and writing in Mandarin. Note that they will not perform the experiments all together.
To design the task, select 180 characters from the Chinese character database. Use 90 high-frequency characters, those that occur more than 100 times per million, and 90 low-frequency characters, those that only occur between one to 15 times per million characters. Ensure that the characters contain three regularity types, regular, in which the phonetic radical and the character share the same pronunciation, irregular, in which there are differences between their pronunciations, and non-phonogram, in which the character cannot be defined as a phonogram.
Next, classify each character into one of six categories, one, high-frequency regular, two, high-frequency irregular, three, high-frequency non-phonogram, four, low-frequency regular, five, low-frequency irregular, and six, low-frequency non-phonogram. Use an outline font design program to construct 180 pseudo-characters by keeping the right radical of the characters and changing the left radical to another one. Ensure that there is no significant difference in the numbers of strokes between the characters and pseudo-characters.
To do this, start the outline font standard program. When a dialogue box appears, click the ok button and start the program to construct the pseudo-characters. Click reference in the menu to pull up the reference panel and choose a proper font.
Input one real character in the black box, and click the ok button, which will show two panels side-by-side on the screen. In the right panel, use the free selection button to select the left radical of this real character with a circle. Move the left radical to the left panel to make the left radical of the pseudo-character.
Next, click reference and adopt similar procedures to select the right radical of a different real character. Move the right radical of this real character to the left panel. Then, put the two radicals together to form the full pseudo-character.
Ensure that the combination of those two radicals is meaningless in the lexicon. Set up the lexical decision task, or LDT, by using standard experimental software to program the experiment according to software protocols. Ensure that 50%of the stimuli are characters for the yes response, and the others are pseudo-characters for the no response.
Ask the participant to judge whether the written stimulus appearing on the screen is a real character or not. Instruct them to respond as accurately and quickly as possible by pressing a corresponding key for either yes or no. Remind the participant to use their right hand when making responses.
Note that on-screen instructions should be in the target language. The English instructions in this video are merely for demonstration and in actual situations, they are presented in Chinese. Begin the experiment with a 12 trial practice session.
Start each trial with a cross to indicate a fixation point at the center of the screen for 500 milliseconds, which is accompanied by a 100 Hertz warning tone for 200 milliseconds. Then, show a blank screen for 500 milliseconds. Next, show the target character on the screen until the computer detects the participant's key response.
Set the inter-trial interval to 1, 000 milliseconds, and measure the response time from the onset of the target character until a key press response is made. For the naming task, use standard experimental software to program the experiment according to software protocols. Ensure that all of the stimuli are real characters.
Ask the participant to pronounce the written characters on the screen. Instruct them to make an oral response as accurately and quickly as possible, and judge this oral response as correct only when a participant pronounces it with the one correct pronunciation. Use a microphone with a voice-activated circuit to detect the oral responses of the participants.
Just as done with the LDT, start each trial with a cross to indicate a fixation point at the center of the screen for 500 milliseconds, which is accompanied by a 100 Hertz warning tone for 200 milliseconds. Then, show a blank screen for 500 milliseconds, followed by the target character on the screen. Measure the response time and accuracy rate of the participant's response.
This protocol investigates Chinese character recognition by comparing the frequency effect between the LDT and naming tasks. Participants performed faster and more accurately for high-frequency characters, which is known as the frequency effect. Furthermore, in the naming task, a regularity effect was observed, which indicated that participants responded slower to the low-frequency irregular characters and non-phonograms.
Once mastered, this technique can be done in about seven minute if it is performed properly. While attempting this procedure, it's important for researchers to remember to recruit sufficient participant and select proper stimuli. Following this procedure, other methods like FMRI can be performed to answer additional questions, like which neural correlates are associated with related cognitive processes?
After this development, this technique paved the way for researchers in the field of experimental and cognitive psychology to explore psycholinguistic topics such as the existence of prelexical phonology and Chinese recognition. After watching this video, you should have a good understanding of how to elucidate the role of phonology and Chinese recognition by comparing results from the lexical decision task and the naming task.
