The effect of cognitive demand on performance of an executive function task following wild blueberry supplementation in 7 to 10 years old children

Abstract

The cognitive benefits of acute flavonoid interventions have been well documented, however, research to date has found that, depending on developmental stage, these benefits manifest themselves in different cognitive domains. It is argued that the lack of global cognitive effects following flavonoid intervention may be a result of insufficient task sensitivity for those domains where no benefits are found. In children, executive function is a cognitive domain which has shown little apparent benefit following flavonoid intervention. Here, we describe a Modified Attention Network Task (MANT) designed to vary levels of cognitive demand across trials in order to investigate whether flavonoid related benefits can be shown for executive function when task sensitivity is carefully manipulated. Twenty-one children were recruited to a double blind cross-over study consuming 30 g freeze dried blueberry powder (WBB) or placebo before being tested at 3 hours. Performance in the WBB condition was found to be significantly faster in comparison to placebo particularly on more cognitively demanding incongruent and high load trials. Trials in which a visual cue alerted participants to the imminent appearance of the target also showed better performance following WBB administration. We conclude that WBB administration can enhance executive function during demanding elements of a task, but that the complexity and demand of the task as a whole may be equally important to performance.

A Randomized, Double-Blinded, Placebo-Controlled Study to Compare the Safety and Efficacy of Low Dose Enhanced Wild Blueberry Powder and Wild Blueberry Extract (ThinkBlue™) in Maintenance of Episodic and Working Memory in Older Adults

“…In healthy older adults, 90-day supplementation with 24 g of freeze-dried blueberry powder demonstrated significant improvement in repetition errors in the California Verbal Learning Task (CVLT) and reduced switch cost on a task-switching test [ 18 ]. Linked to the findings of Whyte et al [ 17 ], Miller at al., noted that their significant findings were found on the more challenging cognitive tasks in their battery. Similarly, in older adults with mild cognitive impairment (MCI), participants showed better episodic memory performance on the CVLT and Verbal Paired Associate Learning Test after 12-weeks consumption of 400–600 mL of wild blueberry juice [ 19 ].…”

“…Firstly, the Rey’s Auditory Verbal Learning task (RAVLT) targeted verbal episodic memory and examined performance in learning, memory recall, and recognition. The procedure followed that previously described by Lezak [ 29 ], and as amended by Whyte, and Williams [ 17 ]. Measures of immediate recall, total acquisition, amount learned, proactive and retroactive interference, delayed recall, and word recognition were evaluated.…”

“…The Sternberg memory scanning task [ 17 , 35 ] followed the same procedure as described previously by Bell et al [ 34 ]. Reaction time and accuracy were recorded for each trial.…”

“…In children, improvements have been observed acutely following consumption of 200 g of blueberries in delayed recalled accuracy of the Rey’s Auditory Verbal Learning Test (RAVLT) and in delayed word recognition of this same task following consumption of 15 and 30 g of wild blueberry powder (WBP) respectively [ 15 , 16 ]. More recently, Whyte et al [ 17 ] manipulated cognitive demand in a modified attention network task finding that, following acute intervention with 30 g WBP, children performed more effectively on the more cognitively demanding trials of the task. This indicates that WBP intervention may be particularly effective where cognitive demand or difficulty is comparatively high, and participants are not able to perform the tasks at, or near, ceiling.…”

Changes in Polyphenolics during Storage of Products Prepared with Freeze-Dried Wild Blueberry Powder

“…These health-promoting effects are due to a myriad of mechanisms associated with blueberry polyphenolics, including prevention of oxidative stress and inflammation, and vaso-and lipid modulation [14][15][16]. Many human studies reporting positive health outcomes have used freeze-dried wild blueberry (WBB) powder [17][18][19][20][21], which is a natural source of concentrated polyphenolics. However, the freeze-dried WBB powder may be tart or astringent and not always palatable to consume.…”