There is profound concern and evidence that extensive overdependence on digital tools may lead to diminishing the ability to solve a complex problem that needs concentrating on the contours and the solution of the problem, not just for hours, but even for months. There is apprehension that if the new generation of humanity loses this power of concentration and listening to others’ views.

1. The nature of deep work and concentration
Serious research—whether in physics, philosophy, or social science—depends on sustained, uninterrupted attention over long periods. It requires not only memory and reasoning but also patience, the ability to tolerate ambiguity, and openness to dialogue with others’ perspectives. These are cognitive endurance skills, not just quick problem-solving tricks.

2. Evidence of digital distraction
There is robust evidence that constant reliance on digital tools (especially smartphones and apps designed for immediate engagement) fragments attention. Studies have shown that frequent multitaskers perform worse on tests of sustained concentration and working memory (Ophir et al., 2009). Similarly, students exposed to regular digital interruptions during study sessions retain less information and show diminished problem-solving performance.

3. Shallow vs. deep thinking
Digital platforms encourage “shallow” cognitive engagement—skimming, scanning, reacting—rather than “deep” processing. Nicholas Carr’s The Shallows argued that the very neuroplasticity that enables us to adapt to tools also reshapes us away from deep reading and slow, effortful thought if we rarely practice them. The worry is that if generations grow up constantly switching contexts, they may lose the habit (and perhaps even some neural architecture) for prolonged concentration.

4. Listening and intellectual patience
Research culture also thrives on dialogue—reading others’ work, critiquing, debating. If digital environments foster impatience, echo chambers, or the urge for instant gratification, the capacity to sit with opposing views or slowly build consensus could weaken. This isn’t just a cognitive risk but also a cultural one for the research ecosystem.

5. Counterpoint: tools as enablers
However, it’s important to balance the picture. Digital tools also enormously accelerate research—by giving access to vast data, computational modelling, and global collaboration. Just as calculators did not end mathematics but reshaped it, digital tools might shift research away from rote memorisation and toward synthesis, creativity, and design. The key risk lies in whether humans maintain the discipline of deep focus alongside these conveniences.

6. Validity of the apprehension
So, how valid is the worry? It is valid, but not inevitable. If future generations are never trained in sustained focus and intellectual patience, then yes—serious research may suffer. Complex problems (like climate change, AI safety, or cancer biology) require months or years of deep thinking, not quick look-ups. But if education, culture, and institutions deliberately cultivate deep work habits—through practices like distraction-free research environments, long-form writing, and debate training—then digital tools can coexist with, rather than replace, deep cognition.

A classic set of experiments on visual development and brain plasticity, most famously carried out by David Hubel and Torsten Wiesel in the 1960s. These studies transformed our understanding of how experience shapes the brain during early life.

In their experiment, newborn mice (and also kittens in some versions) had one eyelid sutured shut shortly after birth. This meant that during a crucial window of early postnatal life—the so-called critical period—visual input from one eye was completely blocked. Importantly, the eye itself remained physically intact; the manipulation only restricted patterned visual experience from reaching the brain.

When the deprived eyelid was reopened later, the animals could technically receive visual input again. However, electrophysiological recordings from neurons in the visual cortex revealed a striking imbalance. Very few neurons responded to stimulation of the previously closed eye, whereas the majority responded strongly to the eye that had remained open. In effect, the brain’s wiring had been permanently shifted to favour the open eye.

Further analysis showed that cortical areas that should have been devoted to the closed eye had instead been “taken over” by pathways from the open eye. This reallocation of cortical territory was not simply a temporary adaptation but a long-lasting change in neural circuitry. Even though the deprived eye could detect light, the brain no longer processed its signals effectively, leading to functional blindness from cortical neglect.

These findings established two crucial principles. First, there is a critical period in early development when sensory experience powerfully shapes the organisation of the brain’s circuits. Second, deprivation of input during this period can lead to irreversible deficits, because once cortical territory is reassigned, it cannot easily be reclaimed. The work not only explained why early detection and treatment of conditions like childhood cataracts or strabismus (squint) is essential, but also laid the foundation for the modern concept of neural plasticity.

Back then, glass or metal microelectrodes had to be physically placed inside or on the surface of the brain to measure the activity of individual neurons or small populations. This was invasive, and although still widely used in animal neuroscience, technology has broadened enormously.

Today, several non-invasive or minimally invasive techniques exist:

• EEG (Electroencephalography): Electrodes are placed on the scalp to detect summed electrical activity from large populations of neurons. It doesn’t require penetration, but the spatial resolution is limited compared to intracranial recordings.
• MEG (Magnetoencephalography): Measures magnetic fields produced by brain activity. It’s entirely non-invasive and provides millisecond-level temporal resolution, though it’s very expensive and less precise for deep brain structures.
• fMRI (Functional Magnetic Resonance Imaging): Not an electrical recording method, but it detects blood-oxygen-level changes linked to neuronal activity. It gives excellent spatial maps but only indirect and slow information about neural firing.
• Optogenetics and calcium imaging (mostly in animals): Instead of electrodes, genetically encoded indicators and lasers allow researchers to “see” neural activity with fluorescent light. This provides high resolution without having to poke electrodes deep into tissue, though it usually requires genetic manipulation.
• High-density electrode arrays (like Neuropixels): For invasive animal research, these can record from thousands of neurons at once with much less damage than the old single electrodes.

So to answer directly: if you want fine-grained, single-neuron resolution, electrodes (or optical probes) are still needed. But if the goal is to study overall patterns of brain activity, we now have non-invasive tools that don’t require putting electrodes inside the brain.

It is important to emphasise that why is it that child nutrition is considered a now-or-never issue. Here’s why stunting and wasting in early life often cannot be fully reversed in adulthood, even if nutrition later improves:

1. Critical windows of growth and development
Just like in the brain experiments we talked about earlier, the human body also has critical periods. The first 1,000 days of life (from conception to around age 2) are when growth in height, brain development, and organ maturation happen most rapidly. If the child is deprived of energy, protein, and micronutrients during this window, the body prioritises survival over growth. Later, when nutrition improves, the “blueprint” for growth has already been altered—so catch-up is partial at best.

2. Permanent effects on bone growth
Linear growth (height) depends on the activity of growth plates in bones. These plates are most active in infancy and early childhood. Malnutrition during this time reduces their activity and can even cause premature closure. Once the growth plates close, even the best diet in adulthood cannot add height. That’s why stunting (low height-for-age) tends to persist lifelong.

3. Brain and cognitive development
Undernutrition in early years interferes with synapse formation, myelination, and overall brain wiring. Later nutrition can support maintenance, but it cannot “rewind” missed opportunities for neural connections. This is why early malnutrition often correlates with lower educational performance and reduced productivity in adulthood.

4. Metabolic “programming”
Children who face undernutrition adapt by altering metabolism—slowing growth, lowering muscle mass, and sometimes conserving fat. This “programming” sticks, so even if food is abundant later, the body doesn’t simply reset to a normal growth trajectory. Instead, adults who were stunted as children are at higher risk of obesity, diabetes, and heart disease.

5. Wasting vs. stunting
Wasting (low weight-for-height) is more immediately reversible than stunting. With proper feeding, wasted children can regain weight relatively quickly. But if wasting is severe and prolonged during critical developmental years, it contributes to stunting, which is far harder to undo.

So, in short: nutrition in adulthood can improve strength, immunity, and overall health, but it can’t fully undo the structural, cognitive, and metabolic consequences of early-life undernutrition.

A demonstration of experience-dependent brain plasticity in adults is The London taxi driver study (carried out by Eleanor Maguire and colleagues around 2000). The study focused on drivers who had passed “The Knowledge,” the rigorous test requiring mastery of London’s complex street network. Here are the major findings:

1. Enlargement of the hippocampus
MRI scans showed that licensed London taxi drivers had a significantly larger posterior hippocampus compared to control subjects. The hippocampus is a brain region crucial for spatial navigation and memory. This finding indicated that the demands of navigating London’s intricate roads reshaped their brains structurally.

2. Trade-off in hippocampal regions
While the posterior hippocampus was larger, the anterior hippocampus was slightly smaller in taxi drivers compared to controls. This suggested that the brain might “allocate” neural resources differently, with growth in one subregion being balanced by reduction in another.

3. Correlation with years of experience
The longer the taxi drivers had been on the job, the more pronounced the enlargement of the posterior hippocampus. This supported a causal link: it wasn’t just that people with naturally large hippocampi became taxi drivers, but rather that the training and years of navigation changed the brain.

4. Functional consequences for memory
Taxi drivers were better at spatial memory tasks—recalling routes and landmarks—than non-drivers. However, they performed worse on certain tests of visual memory for complex figures, hinting at a possible cognitive trade-off: intense spatial expertise may come at the cost of other memory types.

5. Evidence for adult neuroplasticity
Perhaps the most groundbreaking conclusion was that the adult brain is not fixed. Even in adulthood, extensive learning and experience can alter brain structure. This challenged the older view that neuroplasticity was limited to childhood.

In essence, the London taxi driver study showed that the brain can “rewire” itself structurally in response to the mental demands of a profession, providing one of the strongest natural examples of neuroplasticity in humans.