Feeling overwhelmed? Struggling to concentrate? Finding yourself jumping between tasks but not making progress on any of them?
Many of the clients I work with describe feeling frustrated with themselves when this happens. They wonder why tasks that normally feel manageable suddenly feel difficult, why they can’t focus, or why they seem to be working harder but achieving less. Often, the issue isn’t motivation or resilience—it’s that their cognitive capacity has become overloaded.
From a psychological and neuroscience perspective, the answer is often simpler than we think. your brain may be at or beyond its cognitive capacity.
What is cognitive capacity?
Cognitive capacity refers to the amount of information and mental effort your brain can manage at any one time. While our brains are incredibly powerful, they also have limitations, particularly the prefrontal cortex (PFC), the area responsible for planning, decision-making, problem-solving, attention, and self-control.
The challenge is that many of us try to operate as though our cognitive resources are unlimited. They aren’t.
The limitations of the brain
Research by Lorenc, et al (2021) identifies some of the limiatations of the brain that are helpful to be aware of;
- It is energy intensive and requires significant resources to function effectively
- It can only hold a small amount of information in working memory at one time
- It processes information sequentially, meaning true multitasking is difficult
- It is highly sensitive to distraction, both internal and external
This means that every decision, interruption, notification, email, worry, or competing demand places additional strain on a system that already has limited capacity.
When cognitive demands exceed our available resources, we can experience:
- Mental fatigue
- Reduced concentration
- Poor decision-making
- Increased stress and irritability
- Feelings of overwhelm
This is not a sign of weakness. It reflects how the brain is designed.
The myth of multitasking
Many of us pride ourselves on multitasking. However, neuroscience tells us that the brain is largely a serial processor, it performs best when focusing on one cognitively demanding task at a time.
What feels like multitasking is usually task-switching. Each switch forces the brain to refocus, using extra mental energy and reducing efficiency. The result? We feel busy, but not necessarily productive.
Finding your cognitive capacity sweet spot
The relationship between stress and performance is often described by the Yerkes-Dodson Law. Too little stimulation can lead to boredom and disengagement. Too much can lead to overwhelm and reduced performance.
Somewhere in the middle lies your “sweet spot”—the point where you are sufficiently challenged to be engaged but not so overloaded that your thinking becomes impaired.
Part of developing self-awareness is learning to recognise what this sweet spot looks like for you.
Not all tasks require the same amount of brain power
One of the most useful ways to think about cognitive capacity is to recognise that not all tasks place the same demands on the brain.
Level 1: Low cognitive demand
These are familiar, routine tasks that require relatively little mental effort.
Examples:
- Deleting emails
- Administrative tasks
- Scheduling appointments
These tasks often feel rewarding because they are clear, predictable, and easy to complete.
Level 2: Moderate cognitive demand
These tasks require more attention, working memory, and judgement.
Examples:
- Writing notes from a meeting
- Summarising information
- Reflecting on recent events
These tasks involve some ambiguity and therefore require more cognitive effort.
Level 3: High cognitive demand
These tasks require the greatest amount of mental energy.
Examples:
- Strategic thinking
- Problem-solving
- Decision-making
- Creative work
- Developing a new project or presentation
These tasks often involve uncertainty and complexity, which can trigger a stronger threat response in the brain. Interestingly, they are also often the tasks we are most likely to avoid when we’re feeling overwhelmed.
Stategies to Improve Cognitive Capacity
Rather than expecting yourself to perform at maximum capacity all day, it can be helpful to organise your workload around how the brain actually functions.
Notice your peak performance window
- When during the day do you think most clearly?
- For some people it’s first thing in the morning. For others it’s later in the day once they’ve settled into a rhythm.
- Try to schedule your Level 3 tasks during these periods.
Match the task to the energy available
- When your cognitive energy is low, focus on Level 1 tasks.
- Reserve your highest-quality thinking time for work that genuinely requires it.
Reduce unnecessary distractions
Every interruption consumes cognitive resources.
Where possible:
- Silence notifications
- Close unnecessary tabs
- Create focused periods of work
- Take regular breaks to recharge
Respect your limitations
- Your brain is not a machine. It performs best when given opportunities to rest, recover, and refuel.
- Working longer is not always the same as working better.
A final thought
Many of us judge ourselves harshly when we feel overwhelmed, distracted, or mentally exhausted. Yet often the issue isn’t motivation or capability, it’s capacity.
The question may not be, “What’s wrong with me?”
Instead, it might be:
“Am I expecting more from my brain than it can realistically deliver right now?”
Understanding your cognitive capacity isn’t about lowering your expectations. It’s about working more effectively with the brain you have.
What is one change you could make to better support your cognitive capacity?
Lorenc, E. S., Mallett, R., & Lewis-Peacock, J. A. (2021). Distraction in Visual Working Memory: Resistance is Not Futile. Trends in cognitive sciences, 25(3), 228–239. https://doi.org/10.1016/j.tics.2020.12.004
