We’re all time-poor, so multi-tasking is seen as a necessity of modern living. We answer work emails while watching TV, make shopping lists in meetings and listen to podcasts when doing the dishes. We attempt to split our attention countless times a day when juggling both mundane and important tasks.

But doing two things at the same time isn’t always as productive or safe as focusing on one thing at a time.

The dilemma with multi-tasking is that when tasks become complex or energy-demanding, like driving a car while talking on the phone, our performance often drops on one or both.

Here’s why – and how our ability to multi-task changes as we age.

Doing more things, but less effectively

The issue with multi-tasking at a brain level, is that two tasks performed at the same time often compete for common neural pathways – like two intersecting streams of traffic on a road.

In particular, the brain’s planning centres in the frontal cortex (and connections to parieto-cerebellar system, among others) are needed for both motor and cognitive tasks. The more tasks rely on the same sensory system, like vision, the greater the interference.

This is why multi-tasking, such as talking on the phone, while driving can be risky. It takes longer to react to critical events, such as a car braking suddenly, and you have a higher risk of missing critical signals, such as a red light.

The more involved the phone conversation, the higher the accident risk, even when talking “hands-free”.

Generally, the more skilled you are on a primary motor task, the better able you are to juggle another task at the same time. Skilled surgeons, for example, can multitask more effectively than residents, which is reassuring in a busy operating suite.

Highly automated skills and efficient brain processes mean greater flexibility when multi-tasking.

Adults are better at multi-tasking than kids

Both brain capacity and experience endow adults with a greater capacity for multi-tasking compared with children.

You may have noticed that when you start thinking about a problem, you walk more slowly, and sometimes to a standstill if deep in thought. The ability to walk and think at the same time gets better over childhood and adolescence, as do other types of multi-tasking.

When children do these two things at once, their walking speed and smoothness both wane, particularly when also doing a memory task (like recalling a sequence of numbers), verbal fluency task (like naming animals) or a fine-motor task (like buttoning up a shirt). Alternately, outside the lab, the cognitive task might fall by wayside as the motor goal takes precedence.

Brain maturation has a lot to do with these age differences. A larger prefrontal cortex helps share cognitive resources between tasks, thereby reducing the costs. This means better capacity to maintain performance at or near single-task levels.

The white matter tract that connects our two hemispheres (the corpus callosum) also takes a long time to fully mature, placing limits on how well children can walk around and do manual tasks (like texting on a phone) together.

For a child or adult with motor skill difficulties, or developmental coordination disorder, multi-tastking errors are more common. Simply standing still while solving a visual task (like judging which of two lines is longer) is hard. When walking, it takes much longer to complete a path if it also involves cognitive effort along the way. So you can imagine how difficult walking to school could be.

What about as we approach older age?

Older adults are more prone to multi-tasking errors. When walking, for example, adding another task generally means older adults walk much slower and with less fluid movement than younger adults.

These age differences are even more pronounced when obstacles must be avoided or the path is winding or uneven.

Older adults tend to enlist more of their prefrontal cortex when walking and, especially, when multi-tasking. This creates more interference when the same brain networks are also enlisted to perform a cognitive task.

These age differences in performance of multi-tasking might be more “compensatory” than anything else, allowing older adults more time and safety when negotiating events around them.

Older people can practise and improve

Testing multi-tasking capabilities can tell clinicians about an older patient’s risk of future falls better than an assessment of walking alone, even for healthy people living in the community.

Testing can be as simple as asking someone to walk a path while either mentally subtracting by sevens, carrying a cup and saucer, or balancing a ball on a tray.

Patients can then practise and improve these abilities by, for example, pedalling an exercise bike or walking on a treadmill while composing a poem, making a shopping list, or playing a word game.

The goal is for patients to be able to divide their attention more efficiently across two tasks and to ignore distractions, improving speed and balance.

There are times when we do think better when moving

Let’s not forget that a good walk can help unclutter our mind and promote creative thought. And, some research shows walking can improve our ability to search and respond to visual events in the environment.

But often, it’s better to focus on one thing at a time

We often overlook the emotional and energy costs of multi-tasking when time-pressured. In many areas of life – home, work and school – we think it will save us time and energy. But the reality can be different.

Multi-tasking can sometimes sap our reserves and create stress, raising our cortisol levels, especially when we’re time-pressured. If such performance is sustained over long periods, it can leave you feeling fatigued or just plain empty.

Deep thinking is energy demanding by itself and so caution is sometimes warranted when acting at the same time – such as being immersed in deep thought while crossing a busy road, descending steep stairs, using power tools, or climbing a ladder.

So, pick a good time to ask someone a vexed question – perhaps not while they’re cutting vegetables with a sharp knife. Sometimes, it’s better to focus on one thing at a time.

Peter Wilson, Professor of Developmental Psychology, Australian Catholic University

This article is republished from The Conversation under a Creative Commons license. Read the original article.

As of January this year, Aotearoa New Zealand became just the second country (after Canada) to adopt a groundbreaking new procedure for patients experiencing cardiac arrest.

Known as “double sequential external defibrillation” (DSED), it will change initial emergency response strategies and potentially improve survival rates for some patients.

Surviving cardiac arrest hinges crucially on effective resuscitation. When the heart is working normally, electrical pulses travel through its muscular walls creating regular, co-ordinated contractions.

But if normal electrical rhythms are disrupted, heartbeats can become unco-ordinated and ineffective, or cease entirely, leading to cardiac arrest.

Defibrillation is a cornerstone resuscitation method. It gives the heart a powerful electric shock to terminate the abnormal electrical activity. This allows the heart to re-establish its regular rhythm.

Its success hinges on the underlying dysfunctional heart rhythm and the proper positioning of the defibrillation pads that deliver the shock. The new procedure will provide a second option when standard positioning is not effective.

Using two defibrillators

During standard defibrillation, one pad is placed on the right side of the chest just below the collarbone. A second pad is placed below the left armpit. Shocks are given every two minutes.

Early defibrillation can dramatically improve the likelihood of surviving a cardiac arrest. However, around 20% of patients whose cardiac arrest is caused by “ventricular fibrillation” or “pulseless ventricular tachycardia” do not respond to the standard defibrillation approach. Both conditions are characterised by abnormal activity in the heart ventricles.

DSED is a novel method that provides rapid sequential shocks to the heart using two defibrillators. The pads are attached in two different locations: one on the front and side of the chest, the other on the front and back.

A single operator activates the defibrillators in sequence, with one hand moving from the first to the second. According to a recent randomised trial in Canada, this approach could more than double the chances of survival for patients with ventricular fibrillation or pulseless ventricular tachycardia who are not responding to standard shocks.

The second shock is thought to improve the chances of eliminating persistent abnormal electrical activity. It delivers more total energy to the heart, travelling along a different pathway closer to the heart’s left ventricle.

Evidence of success

New Zealand ambulance data from 2020 to 2023 identified about 1,390 people who could potentially benefit from novel defibrillation methods. This group has a current survival rate of only 14%.

Recognising the potential for DSED to dramatically improve survival for these patients, the National Ambulance Sector Clinical Working Group updated the clinical procedures and guidelines for emergency medical services personnel.

The guidelines now specify that if ventricular fibrillation or pulseless ventricular tachycardia persist after two shocks with standard defibrillation, the DSED method should be administered. Two defibrillators need to be available, and staff must be trained in the new approach.

Though the existing evidence for DSED is compelling, until recently it was based on theory and a small number of potentially biased observational studies. The Canadian trial was the first to directly compare DSED to standard treatment.

From a total of 261 patients, 30.4% treated with this strategy survived, compared to 13.3% when standard resuscitation protocols were followed.

The design of the trial minimised the risk of other factors confounding results. It provides confidence that survival improvements were due to the defibrillation approach and not regional differences in resources and training.

The study also corroborates and builds on existing theoretical and clinical scientific evidence. As the trial was stopped early due to the COVID-19 pandemic, however, the researchers could recruit fewer than half of the numbers planned for the study.

Despite these and other limitations, the international group of experts that advises on best practice for resuscitation updated its recommendations in 2023 in response to the trial results. It suggested (with caution) that emergency medical services consider DSED for patients with ventricular fibrillation or pulseless ventricular tachycardia who are not responding to standard treatment.

Training and implementation

Although the evidence is still emerging, implementation of DSED by emergency services in New Zealand has implications beyond the care of patients nationally. It is also a key step in advancing knowledge about optimal resuscitation strategies globally.

There are always concerns when translating an intervention from a controlled research environment to the relative disorder of the real world. But the balance of evidence was carefully considered before making the decision to change procedures for a group of patients who have a low likelihood of survival with current treatment.

Before using DSED, emergency medical personnel undergo mandatory education, simulation and training. Implementation is closely monitored to determine its impact.

Hospitals and emergency departments have been informed of the protocol changes and been given opportunities to ask questions and give feedback. As part of the implementation, the St John ambulance service will perform case reviews in addition to wider monitoring to ensure patient safety is prioritised.

Ultimately, those involved are optimistic this change to cardiac arrest management in New Zealand will have a positive impact on survival for affected patients.

Vinuli Withanarachchie, PhD candidate, College of Health, Massey University; Bridget Dicker, Associate Professor of Paramedicine, Auckland University of Technology, and Sarah Maessen, Research Associate, Auckland University of Technology

This article is republished from The Conversation under a Creative Commons license. Read the original article.

At one time or another, you’ve probably come across someone who is lactose intolerant and might experience some unpleasant gut symptoms if they have dairy. Maybe it’s you – food intolerances are estimated to affect up to 25% of Australians.

Meanwhile, cow’s milk allergy is one of the most common food allergies in infants and young children, affecting around one in 100 infants.

But what’s the difference between food allergies and food intolerances? While they might seem alike, there are some fundamental differences between the two.

What is an allergy?

Australia has one of the highest rates of food allergies in the world. Food allergies can develop at any age but are more common in children, affecting more than 10% of one-year-olds and 6% of children at age ten.

A food allergy happens when the body’s immune system mistakenly reacts to certain foods as if they were dangerous. The most common foods that trigger allergies include eggs, peanuts and other nuts, milk, shellfish, fish, soy and wheat.

Mild to moderate signs of food allergy include a swollen face, lips or eyes; hives or welts on your skin; or vomiting. A severe allergic reaction (called anaphylaxis) can cause trouble breathing, persistent dizziness or collapse.

What is an intolerance?

Food intolerances (sometimes called non-allergic reactions) are also reactions to food, but they don’t involve your immune system.

For example, lactose intolerance is a metabolic condition that happens when the body doesn’t produce enough lactase. This enzyme is needed to break down the lactose (a type of sugar) in dairy products.

Food intolerances can also include reactions to natural chemicals in foods (such as salicylates, found in some fruits, vegetables, herbs and spices) and problems with artificial preservatives or flavour enhancers.

Symptoms of food intolerances can include an upset stomach, headaches and fatigue, among others.

Food intolerances don’t cause life-threatening reactions (anaphylaxis) so are less dangerous than allergies in the short term, although they can cause problems in the longer term such as malnutrition.

We don’t know a lot about how common food intolerances are, but they appear to be more commonly reported than allergies. They can develop at any age.

It can be confusing

Some foods, such as peanuts and tree nuts, are more often associated with allergy. Other foods or ingredients, such as caffeine, are more often associated with intolerance.

Meanwhile, certain foods, such as cow’s milk and wheat or gluten (a protein found in wheat, rye and barley), can cause both allergic and non-allergic reactions in different people. But these reactions, even when they’re caused by the same foods, are quite different.

For example, children with a cow’s milk allergy can react to very small amounts of milk, and serious reactions (such as throat swelling or difficulty breathing) can happen within minutes. Conversely, many people with lactose intolerance can tolerate small amounts of lactose without symptoms.

There are other differences too. Cow’s milk allergy is more common in children, though many infants will grow out of this allergy during childhood.

Lactose intolerance is more common in adults, but can also sometimes be temporary. One type of lactose intolerance, secondary lactase deficiency, can be caused by damage to the gut after infection or with medication use (such as antibiotics or cancer treatment). This can go away by itself when the underlying condition resolves or the person stops using the relevant medication.

Whether an allergy or intolerance is likely to be lifelong depends on the food and the reason that the child or adult is reacting to it.

Allergies to some foods, such as milk, egg, wheat and soy, often resolve during childhood, whereas allergies to nuts, fish or shellfish, often (but not always) persist into adulthood. We don’t know much about how likely children are to grow out of different types of food intolerances.

How do you find out what’s wrong?

If you think you may have a food allergy or intolerance, see a doctor.

Allergy tests help doctors find out which foods might be causing your allergic reactions (but can’t diagnose food intolerances). There are two common types: skin prick tests and blood tests.

In a skin prick test, doctors put tiny amounts of allergens (the things that can cause allergies) on your skin and make small pricks to see if your body reacts.

A blood test checks for allergen-specific immunoglobulin E (IgE) antibodies in your blood that show if you might be allergic to a particular food.

Food intolerances can be tricky to figure out because the symptoms depend on what foods you eat and how much. To diagnose them, doctors look at your health history, and may do some tests (such as a breath test). They may ask you to keep a record of foods you eat and timing of symptoms.

A temporary elimination diet, where you stop eating certain foods, can also help to work out which foods you might be intolerant to. But this should only be done with the help of a doctor or dietitian, because eliminating particular foods can lead to nutritional deficiencies, especially in children.

Is there a cure?

There’s currently no cure for food allergies or intolerances. For allergies in particular, it’s important to strictly avoid allergens. This means reading food labels carefully and being vigilant when eating out.

However, researchers are studying a treatment called oral immunotherapy, which may help some people with food allergies become less sensitive to certain foods.

Whether you have a food allergy or intolerance, your doctor or dietitian can help you to make sure you’re eating the right foods.

Victoria Gibson, a Higher Degree by Research student and Research Officer at the School of Nursing, Midwifery and Social Work at the University of Queensland, and Rani Scott-Farmer, a Senior Research Assistant at the University of Queensland, contributed to this article.

Jennifer Koplin, Group Leader, Childhood Allergy & Epidemiology, The University of Queensland and Desalegn Markos Shifti, Postdoctoral Research Fellow, Child Health Research Centre, Faculty of Medicine, The University of Queensland

This article is republished from The Conversation under a Creative Commons license. Read the original article.