The Encoding-Specificity Paradigm indicates that memory recall will be superior when contextual factors are congruent between memory encoding and memory retrieval. However, unlike other contextual conditions (e.g., verbal context, mental operations, global feature context, mood dependency, and physical operations), this paradigm has nearly been ignored in the exercise domain. Thus, the purpose of this study was to examine the Encoding-Specificity Paradigm in the context of exercise and rest conditions. 24 young adults (age: M = 21 years) completed a within-subject, counterbalanced experiment involving four laboratory visits, including 1) R-R (rest-rest) condition, 2) R-E (rest-exercise) condition, 3) E-R (exercise-rest) condition, or 4) E-E (exercise-exercise) condition. The exercise bout included a 15-minute moderate-intensity walk on a treadmill. Memory recall was assessed via a 15 word-list task. Memory recall was greater for R-R (8.71 ± 3.1) versus R-E (7.46 ± 2.8), and similarly, for E-E (8.63 ± 2.7) versus E-R (8.21 ± 2.7). The mean word recall for the congruent and incongruent conditions, respectively, was 8.67 (2.4) and 7.83 (2.4). There was a statistically significant condition effect (F = 5.02; P = .03; partial η² = .18). This experiment provides direct support for the Encoding-Specificity Paradigm in the exercise domain.
The Encoding-Specificity Paradigm (
The transfer-appropriate processing model is an extension of the Encoding-Specificity Paradigm as it relates to broader
Regarding the
For the
The
Specifically, Smith et al., utilized a videotape exposure protocol, which had been employed in previous related research (
Regarding
Of particular interest to our experiment (i.e., examining the Encoding-Specificity Paradigm in the exercise/physical domain), research demonstrates that integrating movement (
Related to physical operations, but with more extensive physical movement,
In alignment with recent recommendations to evaluate memory retrieval within exercise contexts, specifically examining whether congruence of exercise during learning and recall influences accuracy of memory performances (e.g., rest-rest or exercise-exercise), and whether the specific environment (e.g., outdoor vs. indoor) may play an additional role (
Despite considerable extant work demonstrating the effects of verbal context, global environmental context, global feature context, mood dependency, and physical operations couched within the Encoding Specificity Paradigm, a comprehensive exploration of encoding processes specifically within the context of verbal memory, and congruent versus incongruent physical exercise has yet to be conducted. Further, a wealth of research suggests physical movement is capable of effecting favorable outcomes across a variety of mental assessments, including creativity, executive functioning, and learning and memory. Assessing the effects of exercise versus rest at both encoding and retrieval, as well as mismatching these physical operations at encoding and retrieval, will facilitate a deeper understanding of the efficacy of the Encoding Specificity Paradigm. As episodic memories are, among other structures, often encoded via involvement of the left prefrontal cortex and later retrieved via involvement from the right prefrontal cortex and cerebellum, activation of the prefrontal and cerebellar structures with exercise may be a strategy for impacting both encoding and retrieval of episodic information. Thus, it is critical to differentially investigate whether exercise itself is capable of substantively influencing the quality of episodic memory performance, or whether merely maintaining a congruent bodily state at the time of encoding and retrieval is sufficient to elicit performance effects in line with the Encoding Specificity Paradigm. Thus, the purpose of this study was to evaluate the Encoding Specificity Paradigm in the context of exercise. We hypothesize that memory performance would be enhanced during congruent (vs. incongruent) states.
This study was approved by the authors’ institutional review board and all participants provided written consent prior to participation. The present experiment is a within-subject, counterbalanced (via Latin-squares) study design. Participants completed four separate visits, each occurring approximately 48–72 hours apart. Further details on these visits is described below. In brief, 24 participants (college students) were recruited via a non-probability sampling approach (classroom announcements and word-of-mouth). This sample size is consistent with our other related experimental work (
On the first visit, participants self-reported their moderate-to-vigorous physical activity (MVPA) (MVPA min/week) using the two-item Physical Activity Vitals Sign (PAVS) survey (
For each visit, participants listened to a recording of 15 non-semantically related words (from the Toronto Word Poll) via sound-reducing headphones, with the words delivered every 1.5 seconds. The list was played twice, with a 10-second break in between. Each word list was unique for the different visits.
Researchers instructed participants to walk on a treadmill (Woodway treadmill) for 15 minutes and select an appropriate pace by saying “Please select a pace similar to one you would choose if you were late to class. Thus, it will not be a leisurely walk. Nor will it be a run.” The self-selected pace was maintained during the exercise bout (i.e., the speed did not vary). The same speed was used for each of the subsequent visits.
Depending on the visit (counterbalanced), participants either performed the 1) R-R (rest-rest) condition, 2) R-E (rest-exercise) condition, 3) E-R (exercise-rest) condition, or 4) E-E (exercise-exercise) condition.
The R-R condition involved resting for 2-minutes; listening to the word list; resting (sitting) for 20-minutes (“white noise” playing through headphones; no access to cell phone); and then memory recall of the words.
The R-E condition involved resting for 2-minutes; listening to the word list; resting for 17-minutes (“white noise”); walking on treadmill for 3-minutes; and then memory recall during the last 30-seconds of the walk.
The E-R condition involved resting for 2-minutes; walking on treadmill for 3-minutes; listening to the word list during the last 30-seconds of the walk; resting (sitting; “white noise”) for 20-minutes; and then memory recall of the words.
The E-E condition involved resting for 2-minutes; commencement of treadmill walking; after 3-minutes of walking, listened to the word list (while continuing to walk); then continued walking for the next 17-minutes; and during the last 30-seconds of this 20-minute walk, memory recall of the words occurred.
Statistical analyses were computed in SPSS (v. 24). A repeated measures ANOVA was employed, evaluating differences in memory recall across the congruent (R-R, E-E) and incongruent (R-E, E-R) conditions. Partial eta-squared (
Variable | Point Estimate | |
---|---|---|
Age, mean years | 20.9 | 1.8 |
Gender, % Female | 50 | |
Race, % non-Hispanic white | 70.8 | |
Waist circumference, mean cm | 91.7 | 11.0 |
MVPA, mean min/week | 214.7 | 194.6 |
The mean age was approximately 21 years, with the sample equally distributed across gender.
Variable | R-R |
R-E |
E-R |
E-E |
Test-Statistic |
|||||||
---|---|---|---|---|---|---|---|---|---|---|---|---|
DF | ||||||||||||
STAI, mean | 28.1 | 6.6 | 28.0 | 7.1 | 30.2 | 7.6 | 28.9 | 7.7 | 1.34 | .29 | .16 | |
HR at baseline, mean bpm | 76.8 | 10.4 | 76.6 | 9.1 | 75.2 | 8.8 | 75.6 | 8.5 | 0.25 | .85 | .03 | |
HR at encoding, mean bpm | - | - | - | - | 114.3 | 15.3 | 112.8 | 13.9 | 0.75 | .39 | .03 | |
HR at retrieval, mean bpm | 79.5 | 9.9 | 107.1 | 12.2 | 78.3 | 9.8 | 115.1 | 11.2 | 65.4 | .001 | .92 | |
Speed, mean mph | - | - | 3.48 | 0.5 | 3.38 | 0.1 | 3.37 | 0.1 | 1.0 | .38 | .08 |
In direct support of the Encoding-Specific Paradigm, memory recall was greater when there was congruence across the two conditions. That is, memory recall was greater for R-R (8.71 ± 3.1) versus R-E (7.46 ± 2.8), and similarly, for E-E (8.63 ± 2.7) versus E-R (8.21 ± 2.7). The mean word recall for the congruent and incongruent conditions, respectively, was 8.67 (2.4) and 7.83 (2.4). Indeed, there was a statistically significant condition effect (
Unlike other domains (e.g., mental operations, verbal context, global environmental context, global feature context, mood dependency, and physical operations), the application of the Encoding-Specificity Paradigm in the exercise domain is much less investigated. The present experiment provides evidence that this paradigm also extends to ambulatory exercise. That is, matched conditions of rest-rest and exercise-exercise, were superior in enhancing memory recall when compared to mismatched conditions (rest-exercise and exercise-rest).
The present findings are in alignment with the few related studies on this topic.
The present findings, coupled with those of
An interesting observation of our study was that the E-R condition had a higher memory performance than the R-E condition. Although additional work in this area is needed, this suggests that the timing of exercise may play a critical role in memory performance. In alignment with this observation, our other work has shown that when there is a close temporal coupling of exercise with memory encoding, memory performance is enhanced, when compared to other temporal periods (
Strengths of this study include the experimental design and examining the Encoding-Specificity Paradigm in the exercise domain, an under-investigated domain of this paradigm. It would have been interesting if we examined affective state (e.g., mood) not only prior to memory encoding (as we did), but also at memory retrieval, as this would have provided a clue as to whether our observed context-dependency was influenced by condition-related affective state. Previous research suggests that recall may be bolstered by congruence between encoding and retrieval relative to musically-induced mood (e.g., happy music-happy music; sad music-sad music) (
In conclusion, the present study provides direct support for the Encoding-Specificity Paradigm in the exercise domain. The main implications of this finding are the further support of this paradigm within a behavioral domain, as opposed to a health promotion implication of recommending exercise during memory retrieval (e.g., during a classroom exam), as the latter may be challenging and not practical from a logistical perspective. Nevertheless, non-exercise activity thermogenesis (NEAT) encompass locomotor and repetitive movement activities (
The authors have no support to report.
The authors have no funding to report.
The authors have declared that no competing interests exist.