A Training Effect by Three-Month Watering on the Frontal Pole Activation of Healthy Older Adults

The effectiveness of training prefrontal lobe function for suppressing cognitive decline or improving cognitive function has been reported. Some epidemiological studies suggested that gardening activities can contribute to suppression of cognitive decline. In our previous studies using functional Near-Infrared Spectroscopy (fNIRS), we reported the possibility of frontal pole (FP) activation of healthy older adults during gardening activities in the quasi-laboratory setting. The objective of this study was to examine the impacts of a three-month continual practice of the watering task in the actual gardening settings on the FP activation of healthy older adults. The participants were 18 right-handed healthy older adults without a diagnosis of mild cognitive impairment or dementia (M = 71.7 years ± SD 5.0, range: 63 - 84 years) who lived independently at home. We asked the participants to continue watering at home for three months in the same way as the research task in the fNIRS measurement. After a three-month intervention, the participants’ task performance improved compared with that of pre-intervention. In addition, the Oxy-Hb values in the right lateral FP during the third trial in the post-intervention measurement were significantly greater compared with the pre-intervention measurement. This study suggested that even a gardening activity with a small number of processes such as watering, if the activity is continued for a certain period of time, can suppress the decline of the FP activation of healthy older adults. Combination of various gardening activities has the potential to be a further cognitive training for activating the FP.