The role of chronic physical exercise and selective attention at encoding on implicit and explicit memory

ABSTRACT

Despite the evidence revealing benefits of chronic cardiovascular exercise on executive functions, little research has been conducted on long-term memory. We aimed to investigate the effect of physical exercise on implicit and explicit memory when attention was modulated at encoding in two groups of active and sedentary participants. With this purpose, attention was manipulated in a similar way in the implicit and explicit memory tasks by presenting picture outlines of two familiar objects, one in blue and the other in green, and participants were asked to pay attention only to one of them. Implicit memory was assessed through conceptual priming and explicit memory through a free recall task followed by recognition. The results did not reveal significant differences between groups in conceptual priming or free recall. However, in recognition, while both groups had similar discrimination for attended stimuli, active participants showed lower discrimination between unattended and new stimuli. These results suggested that exercise may have effects on specific cognitive processes, that is, that active participants may suppress non-relevant information better than sedentary participants, making the discrimination between unattended and new items more difficult.

KEYWORDS:

• Cardiovascular
• implicit
• explicit
• inhibition
• suppression
• memory

Acknowledgments

We thank all the volunteers from the study, Fabrice B. R. Parmentier for his comments on the manuscript and Laura Pérez for helping with data collection.

Disclosure statement

No potential conflict of interest was reported by the authors.

Notes

1 This variable ISI was included to increase signal sensitivity in an fMRI study, for which this task was originally designed. However, participants from this study did not take part in any neuroimaging experiment.

2 Similar results were obtained when repeated ANOVA was calculated on raw mean RTs, indicating a significant effect of condition, F (1, 72) = 29.56, MSE = 1012.54, p < .001 η² _p = .29, but not of group, F (1, 72) = 1.89, MSE = 51071.03, p = .17, η² _p = .03, or group × condition interaction, F (1, 72) = .00, MSE = 1012.54, p = .99, η² _p = .00.

Additional information

Funding

This study was part of Concepción Padilla’s doctoral thesis (FPI predoctoral studentship from the Ministry of Economy and Competitiveness of Spain, BES-2011–043565) at the University of the Balearic Islands. Concepción Padilla, Julia Mayas, Soledad Ballesteros and Pilar Andrés were supported by research grants from the Spanish Ministry of Science and Innovation (PSI2010–21609-C02-02 and PSI2013-41409R). Soledad Ballesteros and Julia Mayas were also supported by a grant from the Comunidad de Madrid (Biomedical Research, S2010/BMD-2349). The founders had no role in study design, data collection and analysis, or preparation of the manuscript.