Does caffeine modulate verbal working memory processes? An fMRI study

Acute caffeine administration impact on working memory-related brain activation and functional connectivity in the elderly: A BOLD and perfusion MRI study

“…These frontoparietal areas are known to participate in the WM encoding circuit (Klaassen et al, 2013). In the first study that used a very similar activation paradigm in 16 young healthy male participants aged from 25 to 47, caffeine induced an increased BOLD response in the bilateral medial frontopolar cortex extending to the right anterior cingulate cortex (Koppelstaetter et al, 2008). The effect size in our study was substantially higher than that observed by Koppelstaetter and colleagues.…”

“…auditory oddball, visual stimuli), and suggested the presence of a caffeine-mediated neurovascular uncoupling in young individuals characterized by a significant decrease of CBF with a concomitant increase of evoked (and possibly baseline) oxygen metabolism mainly in frontal areas (Perthen et al, 2008;Griffeth et al, 2011;Diukova et al, 2012). Two fMRI activation studies using a placebo-controlled design and working memory (WM) activation paradigms showed a caffeine-induced blood oxygen leveldependent (BOLD) increase in fronto-parietal areas and a decrease in the thalamus (Koppelstaetter et al, 2008;Klaassen et al, 2013) in young to middle-aged volunteers ranging from 25 to 61 years. Previous functional connectivity studies assessed young adults (Rack-Gomer et al, 2009;Rack-Gomer and Liu, 2012;Wong et al, 2012).…”

The effect of caffeine on working memory load-related brain activation in middle-aged males

“…Koppelstaetter et al (2008) demonstrated increased WM load--related activation (N--back task, block design) following caffeine (compared to placebo) administration in prefrontal cortex areas (PFC) associated with executive and attentional functions (in the absence of a significant effect on WM performance). This finding was suggested to reflect a direct effect of caffeine on WM processes.…”

“…We aimed to extend on findings by Koppelstaetter et al (2008) by investigating the effect of caffeine on WM load--related activation during encoding, maintenance and retrieval phases of a WM maintenance task (modified Sternberg task) using an event--related fMRI design. In contrast to Koppelstaetter et al (2008), we tested participants following a day of habitual caffeine consumption, rather than requiring an extended period of caffeine abstinence prior to testing.…”

“…In contrast to Koppelstaetter et al (2008), we tested participants following a day of habitual caffeine consumption, rather than requiring an extended period of caffeine abstinence prior to testing. The advantage of this approach is that the effects of caffeine are investigated in the context of each participant's usual levels of caffeine in the body, instead of in the context of a caffeine withdrawal state.…”