Anderson, J.A.E., Campbell, K.L., Amer, T., Grady, C.L., & Hasher, L. (2014). Timing is everything: Age differences in the cognitive control network are modulated by time of day. American Psychological Association, 1-10 http://dx.doi.org/10.1037/a0037243

The article focused on the behavioral evidence that suggested that the attention-based ability to control distractions was determined by the synchronization of the circadian arousal rhythm that changed across one’s life span. The researchers used Functional Magnetic Resonance Imaging (FMRI) to test neural activity of older and younger adults using superimposed distracters. They found that older adults had cognitive control over distracting information at different times of the day. For instance, older adults tested better in the morning in terms of control, but their cognitive abilities to suppress distracters reduced during the peak hours. The researchers had hypothesized that there were age and individual differences in alertness patterns, that is, the majority of older adults had cognitive control in the morning while young adults shifted towards neutral and evening-type ranges of alertness. Geerligs,

Saliasi, Maurits, Renken, & Lorist (2014) also shared the same view and they explained that present task or behavioral of individuals relied on the engagement of the attention control network such as the dual-task target detection.

Time and age were considered to be the depended variables and the ability to respond to normal vision when distracted with irrelevant pictures such as the word-fragment-completion test. The ability of the either the young adults or the older people eyes’ stimuli to respond to the irrelevant pictures at different times in a day, were intended to measure their cognitive control functions. Adults aged 60-87 years were cognitively normal or corrected-to-normal vision in the morning, but, in the evening, the testing memory for the test showed low performance. On the other hand, young adults had better eye stimuli to recognize pictures in the evening times in a 1-back test flipping images from left to right to test their ability to recognize any shape of the word they had seen.

The researchers used stratified sampling techniques to investigate how cognitive control changes across different ages at different times of the day. The researcher chose participants based on two different groups: 16 young adults aged between 19-30 years and older another group of 16 older adults aged between 60-87 years. The first group was tested using the Flanker test (1-back test) to find the ability of the eyes to respond to images which were presented in a distracting motion. They were tested to find out how much they had memorized the consonants and fragmented sentences in the morning and in the afternoon. The second group of older adults was passed through the same test.

After completing the test, the researchers scanned the participants using the Siemens Trio 3T scanner for processing of the image data in brain produced by the functional neural images. Young adults and older adults who were tested in the morning when scanned under the FMRI, they showed positive scores for ignore words and non-ignore words condition. However, the older adults had negative brain scores when they were tested in the afternoon, indicating that their cognitive functions were not activated; their confidence limit crossed zero. The brain scan results showed that cognitive alertness for both the adults and the young adults was registered in the frontal gyri and parietal regions. The brain activity indicated increased engagement of cognitive controls for the adults in the afternoon. As for the young adults, they had the largest brain activity recorded in cognitive areas in the morning, but, distracting or suppressing material influenced their slowness in the afternoon tests. The researchers found out that their results were conclusive of the circadian arousal patterns. The results demonstrated that the older adults had a low neural activity in early hours than in late hours and the reverse was true for the young adults. What was crucial in this experiment was that the young adults had the ability to activate a set of attention control regions in their brains which helped them to develop alertness in the morning. However, their control declined in the evening. On the other hand, older adults were able to activate a set of attention control regions in the evening and not in the morning. Young adults seemed to have mastered the frontal parietal lobe to be the switch mode in their cognitive alertness while the older adults accessed it in the default mode during the attention networks.

However, there were some implications in this research, from the beginning, some of the participants were disqualified as not being fit for research; one of the older adults was excluded as a result of the incidental result while some younger adults were excluded because of being expectant of the anticipated results. Furthermore, the brain activities observed could mean other engagements during the day which, accompany behavioral differences. There was also the implication that the conclusion to the brain activity could be triggered by the partly by the time of testing and not the age of individuals; revealing extant behavioral work in that age –related decrements could be influenced by the time of testing. The research conducted suits mostly the field of psychology and ageing. I think this article was intended to show how our cognitive alertness changes as one grow old. The point brought out is that young people have cognitive control mechanism that they can trigger to increase their alertness, but it reduces as the day ends as compared to the older people whose control mechanism are not active. However, the research did not elaborate clearly how cognitive control in brain activity differs in both younger adults and older people. I think that the researchers should research the relationship between the alertness and brain activity across different ages to infer that cognitive control reduces with the ageing factor.

References

Anderson, J.A.E., Campbell, K.L., Amer, T., Grady, C.L., & Hasher, L. (2014). Timing is

everything: Age differences in the cognitive control network are modulated by time of

day. American Psychological Association, 1-10 http://dx.doi.org/10.1037/a0037243

Geerligs, L., Saliasi, E., Maurits, N.M., Renken, R.J., & Lorist, M.M. (2014). Brain mechanisms

underlying the effects of aging on different aspects of selective attention. American Psychological Association Journal, 91, 52– 62

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