Associative Memory During Sleep
Summary. In this study, research look at the ability to make association when people are awake and asleep. The main dependent measure is how quickly people decide a string of letters is or isn't a word. The letter string is always preceded by another word (the prime word). If the letter string is a word, it is sometimes proceeded by a strongly associated word (a strong prime), and sometimes the prime word is only weakly related to the second word.
Video. Scientific American Frontiers: Pieces of Mind (1996), What's in a Dream. The segment begins about 30 minutes into the program; pause about 8 minutes into the segment, after Alan Alda says “Here is where the word tests are revealing.” The segment can be viewed online (as of July 2018) -- Season 7, Episode 3.
Original Research. Stickgold, R., Scott, L., Rittenhouse, C. & Hobson, J. A. (1999). Sleep-induced changes in associative memory. Journal of Cognitive Neuroscience, 11, 182-193.
Design. Repeated measures (type of prime).
Statistical Analysis. Paired t-tests. You can give the students the raw data or the summary statistics (the tables contain difference scores).
Published Results. "In the PM and POST [REM] conditions, strong priming was significantly grreater than weak-priming, as would be expected (two-tailed paired t-tests — PM: df = 79, t = 2.53, p = 0.01; POST: df = 81, t = 1.99, p = .05), and a trend in this direction was seen in the NREM condition (df = 47, t = 1.39, p = .17). In contrast, . . . weak primes produced significantly greater priming than strong primes after REM awakenings (df = 103, t = 2.58, p = 0.01)." (p 186).
Published conclusions. "The shift in weak priming seen after REM sleep awakenings suggests that cognition during REM sleep is qualitatively different from that of waking and NREM sleep and may reflect a shift in associative memory systems, a shift that we hypothesize underlies the bizarre and hyperassociative character of REM-sleep dreaming." (p. 182).
Note: The Excel file for this activity contains realistic priming score differences (strong – weak, in msec) for the PM, REM, and NREM conditions.
Summary. In this study, research look at the ability to make association when people are awake and asleep. The main dependent measure is how quickly people decide a string of letters is or isn't a word. The letter string is always preceded by another word (the prime word). If the letter string is a word, it is sometimes proceeded by a strongly associated word (a strong prime), and sometimes the prime word is only weakly related to the second word.
Video. Scientific American Frontiers: Pieces of Mind (1996), What's in a Dream. The segment begins about 30 minutes into the program; pause about 8 minutes into the segment, after Alan Alda says “Here is where the word tests are revealing.” The segment can be viewed online (as of July 2018) -- Season 7, Episode 3.
Original Research. Stickgold, R., Scott, L., Rittenhouse, C. & Hobson, J. A. (1999). Sleep-induced changes in associative memory. Journal of Cognitive Neuroscience, 11, 182-193.
Design. Repeated measures (type of prime).
Statistical Analysis. Paired t-tests. You can give the students the raw data or the summary statistics (the tables contain difference scores).
Published Results. "In the PM and POST [REM] conditions, strong priming was significantly grreater than weak-priming, as would be expected (two-tailed paired t-tests — PM: df = 79, t = 2.53, p = 0.01; POST: df = 81, t = 1.99, p = .05), and a trend in this direction was seen in the NREM condition (df = 47, t = 1.39, p = .17). In contrast, . . . weak primes produced significantly greater priming than strong primes after REM awakenings (df = 103, t = 2.58, p = 0.01)." (p 186).
Published conclusions. "The shift in weak priming seen after REM sleep awakenings suggests that cognition during REM sleep is qualitatively different from that of waking and NREM sleep and may reflect a shift in associative memory systems, a shift that we hypothesize underlies the bizarre and hyperassociative character of REM-sleep dreaming." (p. 182).
Note: The Excel file for this activity contains realistic priming score differences (strong – weak, in msec) for the PM, REM, and NREM conditions.