Modafinil is a wakefulness-promoting agent used to treat excessive sleepiness caused by narcolepsy and shift work sleep disorder (inability to fall asleep or stay asleep during scheduled sleeping hours while on a shift at work). It’s also prescribe along with breathing devices in some cases of sleep apnea.
It was recently found to reduce divergent thinking in healthy participants. It was also found to decrease motivation in a task that requires prefrontal executive function.
How modafinil affects the brain
The ability of modafinil tablet australia to bolster attention levels and cognitive efficiency has led it to be call the crown prince of smart drugs. Its effects on working memory in particular have captured the imagination of stressed students (not to mention the media). But it’s important to remember that few studies have examined its long-term impact on brain health.
Moreover, modafinil has a relatively low liability for abuse and dependence, and it lacks many of the neurochemical and behavioral effects associated with amphetamine. In addition, its affinity for DA transporters and receptors is relatively weak, so it doesn’t trigger the same neurotransmitter release mechanisms that stimulate the dopamine system in amphetamine users.
Our recent fMRI study using seed-base functional connectivity analysis of the BA17 region show that modafinil administration was associate with increased connectivity between this region and the cerebellum (Figure 2). This was a significant drug effect, as evidenced by paired t-tests that controlled for baseline and treatment. Including gender as a nuisance variable.
Further, this drug effect was accompany by changes in V1 connections with the right IFS and left MFG. Both of which are known to be involve in core executive functions, such as inhibitory control and spatial working memory. These results suggest that modafinil increases activity in these frontal regions to re-orient attention and enhance processing speed.
How modafinil affects memory
Many healthy people take modafinil to stay alert or boost cognition. But research on how it influences the brain remains rudimentary. It enhances performance in sleep-deprived people and helps astronauts cope with circadian rhythm disruption. But it does not make you smarter. It is not recommend to be use as a study aid or to help you meet deadlines. It could do you more harm than good if taken as a regular medication.
Our rs-fMRI data show that modafinil increases functional connectivity (FC) between the bilateral primary visual cortex (V1) and prefrontal areas. Such as the right IFS and left MFG. Moreover, the drug also significantly boosts FC between V1 and cerebellar associative areas. Such as the Crus I, Crus II, and VIIIa lobule.
This suggests that the cognitive effects of Modalert 200 Tablet are mainly mediate by changes in central neurotransmitter systems and that a major component of these cognitive effects is to shift individuals on the speed-accuracy curve.
Moreover, modafinil increases the firing rate of hypothalamic arginine-sensitive hippocampus neurons and improves performance on a variety of tasks, including the Tower of London test, delayed match-to-sample, and 5-choice serial reaction time tests.
However, the enhancements observed in these studies are mainly in participants with high IQ (average of 115 in one study). This suggests that higher-order cognitive functions may be more sensitive to the ceiling effects of modafinil than lower-order ones.
How modafinil affects learning
Studies of learning and memory in healthy participants have shown that modafinil improves performance on tasks that require cognitive control. Such as the WCST and a version of the Hayling sentence completion test. In a double-blind placebo-controlled study, modafinil 200 mg reduced errors (compared to placebo) on these tasks.
This improvement was associate with increased activity in the dorsolateral PFC and anterior cingulate cortex measured by resting-state fMRI, and with decrease sensitivity to the central cholinergic antagonist scopolamine (Hart et al, 2006).
Moreover, in a separate study, modafinil was found to enhance cognitive performance in patients with schizophrenia in a double-blind placebo-control experiment. The effect was mediate by fronto-cortical loops and was related to a decrease in inhibitory deficits. Modafinil was also found to enhance visual discrimination learning in these patients. A task that requires attentional set-shifting and is associate with activity in ascending cholinergic systems.
A well-controlled fMRI study of modafinil in healthy volunteers found that the drug improved performance on several tasks. Including divided attention and immediate recall. The improvements were mediate by increase activation of the dorsolateral PFC and frontal eye fields and by changes in the processing of sensory and motor information.
In addition, the study found that modafinil enhanced the ability to inhibit irrelevant responses in a letter-number span task. This result is consistent with the modulation of adrenergic and glutamate pathways by modafinil. Which is know to increase the pool of cerebral glutamate-glutamine and reduce its reuptake by pyramidal cells in the medial PFC.
How modafinil affects mood
Modafinil’s wake-promoting effects match those of stimulants such as amphetamine and methylphenidate. But it has less of a dopamine-increase effect (see fMRI studies in this section). It increases activity in the dorsolateral prefrontal cortex, a subset of Brodmann’s areas 9 and 12, suggesting increased inhibition of prepotent responding.
Modafinil also increases DA activity in the striatum, including the nucleus accumbens, but at lower levels than amphetamine does.
In one double-blind, placebo-controlled fMRI study. Modafinil 200 mg single-dose significantly improved performance in an N-back task and associated cortical activation under intermediate working memory load. As well as in delayed matching tasks and a version of the Tower of London.
However, there was no improvement in arithmetic or perceptual performances. A similar effect was seen in a double-blind. Placebo-control fMRI study using a similar task design with a different test population.
Modafinil has also been show to prevent the cognitive decline cause by narcolepsy, jet lag, shift work, and chronic sleep deprivation. It is believe to improve vigilance and attention by enhancing the availability of several neurotransmitters, including hypocretin, histamine, epinephrine, and GABA. It also increases the availability of glutamate, a key excitatory neurotransmitter.