Effects of post-encoding wakeful rest and study time on long-term memory performance

Figures & data

Figure 1. Experimental procedure. Participants learned two word lists. In the fixed-paced group words were presented for 1250 ms, in the self-paced group participants themselves determined the presentation duration of each word. The critical manipulation occurred after immediate recall of the respective word list. Participants either rested wakefully or solved problems (see Method section). In Experiment 1, a first delayed free recall test took place (fixed-paced condition: after 12–24 min; self-paced condition: after 17–34 min), and again a second delayed free recall test after 7 days. In Experiment 2, only one delayed free recall test took place after 7 days. Participants were not informed about the delayed recall tests. (*) = order of the word lists and post-encoding conditions were counterbalanced across participants.

Table 1. Descriptive statistics of the mean number of correctly recalled words and mean item responses to question on conscious rehearsal (Experiment 1).

		Post-encoding condition
		Rest	Problem solving
		M (SD)	M (SD)
Immediate recall	Fixed-paced	8.92 (2.61)	9.12 (2.58)
	Self-paced	13.00 (1.52)	13.35 (2.00)
First delayed recall	Fixed-paced	6.81 (3.06)	6.88 (3.27)
	Self-paced	11.77 (2.50)	11.19 (3.48)
Second delayed recall	Fixed-paced	5.31 (3.27)	3.73 (2.43)
	Self-paced	8.85 (3.21)	7.85 (4.17)
Conscious rehearsal^a	Fixed-paced	2.00 (1.41)	2.31 (1.54)
	Self-paced	2.69 (1.69)	2.12 (1.82)

Note. ^a = mean item responses on a Likert scale from 1 (not at all) to 7 (very often).

Figure 2. Mean number of correctly recalled words (max = 15 words per list) in Experiment 1 plotted separately for recall (immediate, first delayed, second delayed), study time (fixed-paced, self-paced), and post-encoding condition (rest, problem solving). Error bars represent standard errors of the mean.

Figure 3. Mean number of correctly recalled words (max = 15 words per list) in Experiment 2 plotted separately for recall (immediate, delayed), study time (fixed-paced, self-paced), and post-encoding condition (rest, problem solving). Error bars represent standard errors of the mean.

Table 2. Descriptive statistics of the mean number of correctly recalled words and mean item responses to question on conscious rehearsal (Experiment 2).

		Post-encoding condition
		Rest	Problem solving
		M (SD)	M (SD)
Immediate recall	Fixed-paced	8.12 (1.97)	8.20 (2.27)
	Self-paced	12.56 (2.33)	12.88 (2.46)
Delayed recall	Fixed-paced	2.88 (2.71)	2.48 (1.98)
	Self-paced	5.56 (3.53)	5.52 (3.82)
Conscious rehearsal^a	Fixed-paced	2.60 (1.63)	2.24 (1.30)
	Self-paced	2.28 (1.43)	2.20 (1.50)

Note. ^a = mean item responses on a Likert scale from 1 (not at all) to 7 (very often).