Effects of Pet Insects on Cognitive Function among the Elderly: An fMRI Study

Animal-assisted therapy has positive effects on cognitive function, depression, performance ability, and social functioning in elderly patients. The aim of this study was to evaluate the effects of rearing pet insects on the cognitive function of healthy elderly participants, with fMRI (functional magnetic resonance imaging) being used for this purpose. Community-dwelling right-handed elderly women (≥60 years) with normal cognitive function were enrolled and randomized at a 1:1 ratio into two groups: insect-rearing and control (n = 16) groups, with the insect-rearing group being further classified into two groups for analysis according to the subjects' scores in the Wisconsin Card Sorting Test, WCST) at the baseline fMRI: Insect-rearing group I with a relatively high score (n = 13), and insect-rearing group II with a relatively low score (n = 6). The insect-rearing groups received and reared crickets as pet insects for 8 weeks. The WCST consisted of two variations, a high level baseline (HLB) and semi-WCST version. There was a significant difference accuracy of the HLB-semi-WCST (p < 0.05) in insect-rearing group II after 8 weeks from the baseline test. In the fMRI analysis involving the WCST reaction test, increased activation was observed in the right dorsal lateral prefrontal cortex and parietal cortex in insect-rearing group II when the semi-WCST, rather than the HLB, was performed. Rearing pet insects showed positive effects on executive functions and performance improvement in elderly women. Further larger studies on the effects of pet insects on cognitive function are warranted.