Method
Participants
A total number of 80 healthy college students, aged between 18 and 22 years will be recruited from local universities by mass mails and the subject pool from the Department of Psychology in the CUHK. College students with a history of brain or head injuries, psychological disorders will be excluded. Procrastinators and non-procrastinators are defined by 1 SD above and below the total score of the Procrastination Assessment Scale Students (PASS; Solomon & Rothblum, 1984) respectively.
Measures
1. n-Back Test
The n-Back test is a computerized test in assessing working memory. Similar paradigms have been used in previous NIRS studies on adults and older adults (Ehlis et al., 2008; Yeung et al., 2016). The test consists of …show more content…
HKLLT is a Chinese list-learning test which assesses learning and memory functions. Participants are required to listen and memorize the same list of Chinese words three times, and they need to recall the words as many as they can immediately after each trial. They will be asked to recall the list again after 10 minutes and 30 minutes, in which the experimenters will not repeat the list to the participants. After the 30-minute delayed recall, there will be a recognition task. In this task, a list of words will be given. Participants will be required to distinguish whether the words on the list were included in the previous recall sessions. The number of recalled words each trial will be scored as the recall scores of trials 1 to 5, ranged from 0 to …show more content…
The NIRS device used in the present study is harmless and non-invasive. The machine utilizes near-infrared light of wavelengths 770 and 840 nm and operates by measuring the relative concentration of the oxygenated hemoglobin [oxy-Hb], as well as the deoxygenated hemoglobin ([deoxy-Hb]), in participants’ cerebral blood flow based on the modified Beer-Lambert Law (Delpy et al., 1988). This machine samples at a rate of 12.21 Hz. Sixteen NIRS signals are recorded in between each of the 6 pairs of emitters and detectors, and these emission and detection probes are arranged in a 2 rows x 6 columns matrix on the participant’s forehead, with 3 cm distance between the probes. The primary focus of the present study will be the [oxy-Hb] signal because of the better signal-to-noise ratio, as well as the stronger relationship with the blood oxygenation level dependent (BOLD) signals measured by fMRI (Strangman, Boas, & Sutton,
Participants
A total number of 80 healthy college students, aged between 18 and 22 years will be recruited from local universities by mass mails and the subject pool from the Department of Psychology in the CUHK. College students with a history of brain or head injuries, psychological disorders will be excluded. Procrastinators and non-procrastinators are defined by 1 SD above and below the total score of the Procrastination Assessment Scale Students (PASS; Solomon & Rothblum, 1984) respectively.
Measures
1. n-Back Test
The n-Back test is a computerized test in assessing working memory. Similar paradigms have been used in previous NIRS studies on adults and older adults (Ehlis et al., 2008; Yeung et al., 2016). The test consists of …show more content…
HKLLT is a Chinese list-learning test which assesses learning and memory functions. Participants are required to listen and memorize the same list of Chinese words three times, and they need to recall the words as many as they can immediately after each trial. They will be asked to recall the list again after 10 minutes and 30 minutes, in which the experimenters will not repeat the list to the participants. After the 30-minute delayed recall, there will be a recognition task. In this task, a list of words will be given. Participants will be required to distinguish whether the words on the list were included in the previous recall sessions. The number of recalled words each trial will be scored as the recall scores of trials 1 to 5, ranged from 0 to …show more content…
The NIRS device used in the present study is harmless and non-invasive. The machine utilizes near-infrared light of wavelengths 770 and 840 nm and operates by measuring the relative concentration of the oxygenated hemoglobin [oxy-Hb], as well as the deoxygenated hemoglobin ([deoxy-Hb]), in participants’ cerebral blood flow based on the modified Beer-Lambert Law (Delpy et al., 1988). This machine samples at a rate of 12.21 Hz. Sixteen NIRS signals are recorded in between each of the 6 pairs of emitters and detectors, and these emission and detection probes are arranged in a 2 rows x 6 columns matrix on the participant’s forehead, with 3 cm distance between the probes. The primary focus of the present study will be the [oxy-Hb] signal because of the better signal-to-noise ratio, as well as the stronger relationship with the blood oxygenation level dependent (BOLD) signals measured by fMRI (Strangman, Boas, & Sutton,