The science of consciousness: May 2018

Thursday, May 31, 2018

Cognitive Manipulation by parasites

Parasite-host interactions have been honed over millions of years of evolution, achieving astonishing and sometimes unsettling precision. The variety of parasites capable of manipulating behavior ranges from viruses to insects and even worms. In some of the most intriguing cases, the parasite influences the host brain's neuronal circuits to control its cognitive functions. To maintain long-term behavioral manipulation, the parasite must secrete compounds that can alter gene expression with lasting effects. This allows parasites to hijack the host's decision-making and behavior. Mind-altering manipulation can occur in nearly all animals. However, the phenomenon is often studied in insects because of their simple nervous systems and goal-directed behavior. For example, when presented with two very similar concentrations of the same odor, fruit flies take longer to decide, which can lead to errors.

Suicide manipulation:

Fungal infection manipulates insect behavior. The fungus (Ophiocordyceps unilateralis) infects ants and feeds on their innards. It produces chemicals that alter the ants' navigation, compelling them to leave their nests and seek out a plant in a humid area to climb to its top. The ant then clamps its mandibles around a leaf or leaf stem—a behavior never seen in uninfected ants. The fungus consumes the ant's brain until it produces spores, killing the host. These spores burst and spread from the top of the tree to infect other ants, starting a new cycle.

In another example of parasitic infection, the Lancet liver fluke hijacks the ant's navigation by migrating to its head and settling near a cerebral ganglion. Unlike normal behavior, the infected ant climbs to the tip of a grass blade to be eaten by a grazing animal. The mature fluke expels eggs through the digestive system, infecting more ants.

Yet another case involves a hairworm, which needs water for reproduction. The hairworm infects crickets and other terrestrial insects, developing inside their bodies. When mature, it causes the insect to seek out water. When the insect falls into the water, the parasite emerges to reproduce.

Offspring Care:

Although solitary insects are not known to provide care and safety to their offspring, one of the parasites' most fascinating behaviors is to coerce a host into caring for the parasite's young. Developmental symbiosis occurs when individuals of one species cannot reach maturity without help from another species. For example, a wasp sting injects eggs into a caterpillar. The wasp larvae mature by feeding on the host and emerge after two weeks. However, one or two larvae remain inside the caterpillar. These siblings activate the caterpillar's muscles to violently move its upper body back and forth. This behavior protects the pupae by deterring predators.

The caterpillar's aggressive guarding behavior can also occur in other insects without parasites in their bodies. For example, a single wasp larva develops inside a ladybug, spinning a cocoon between its legs. The ladybug is still alive, but its nervous system triggers twitching and convoluted movements, which keep the wasp pupa safe from potential predators. It is thought that the parasite co-infects with a virus, which induces severe neuropathy and immune responses that cause the motor twitches.

Another example is the butterfly Maculinea arion, whose larvae mimic the smell of those of a particular ant species, causing its members to carry them into their nests, caring for them as their own. The sophistication and effectiveness of parasite infection might have inspired the simulation hypothesis.

Infections in People

The fungal pathogen Candida auris can cause bloodstream infections that can be fatal in 60% of cases. Toxoplasma infection can be linked to mood disorders and mental health issues, including schizophrenia and behavioral changes, such as promoting risky behaviors.

Watch a fascinating video: In Praise of Parasites

https://youtu.be/eOCiIgYQaFo

Discover more about consciousness by ordering my book, "Emotional Reasoning: Insight into the Conscious Experience."

Barnes & Noble

Amazon Books

From the Publisher

Consumption of raw fruits and vegetables might be beneficial for mental health

The old saying, “You are what you eat,” might need a new updating: your mind is shaped by what you eat. A new study found that raw fruit and vegetable intake predicted reduced depressive symptoms and lead to higher positive mood, life satisfaction, and flourishing. The top 10 natural foods related to better mental health were carrots, bananas, apples, dark leafy greens like spinach, grapefruit, lettuce, citrus fruits, fresh berries, cucumber, and kiwifruit.

The study investigated the differential associations between intake of raw fruits and vegetables, compared to processed (cooked or canned) fruits and vegetables, and mental health in young adults. Fruits and vegetables contain a variety of micronutrients critical to physical and psychological function. Antioxidants such as vitamin C and carotenoids might protect the body against oxidative stress. Water-soluble vitamins (vitamin C and B vitamins), and certain minerals (calcium, magnesium, and zinc), are essential for optimal cognitive and emotional functioning. Cooking and processing fruits and vegetables diminish their nutrient levels, limiting the delivery of critical vitamins and other food sources needed for optimal emotional functioning.

A recent discovery that the food you eat influences your brain health gives dietary consideration even more importance and urgency. For example, calorie restriction significantly improves blood supply to the brain. In mice, the Ketogenic Diet (high levels of fat and low levels of carbohydrates) leads to positive results in patients with epilepsy, Parkinson’s disease, and autism. Detailed studies have shown that reduced blood glucose levels and lower body weight might have resulted from the gut's improved microbiome. The most exciting finding has been an amyloid-beta reduction, a known hallmark of Alzheimer’s disease, from the brain. Thus, a Paleo diet, caveman diet, or stone-age diet might protect from Alzheimer's disease.

Picture credit: Fruit market by Diderot

Read the whole article:

Intake of Raw Fruits and Vegetables Is Associated With Better Mental Health Than Intake of Processed Fruits and Vegetables

Find the book on Amazon.

Sunday, May 13, 2018

Adopt a growth mindset by striving toward flexibility

From the Stone Age to the industrial revolution life conditions for the overwhelming majority of people were miserable; they suffered from a seasonal shortage of food, adverse temperatures, threats, and lack of proper housing. Social history, the pomp, the conquest, and the culture rode on the backs of oppressed classes. Religion was the mental comfort and deep-seated hope that gave meaning to life amid the grueling drudgery.

Things cannot be more different at the beginning of the twenty-first century. In most parts of the world, food, clothing, and housing is a natural part of the human condition. In big, overstuffed, middle-class homes, out of season clothes are discarded like garbage. At the time when we achieved never experienced prosperity, we are faced with an epidemic of addictions, alienation, crime, and abuse. Trying to understand the root causes of this seismic social change we need to analyze several factors that had transformed society. Compared to the rigid, impassable class division of yesteryear, social mobility is open to anyone with the drive to succeed. The news is full of examples of tech billionaires and executives who started from modest beginnings. However, the comparison with the proverbial Johnsons can make every member of the society left behind at one time or another. The news, social media, and the internet can serve as a constant reminder of our failure in the rat race. To justify our perceived ineptness, we manufacture imaginary and impassable obstacles to success; theories of unfairness, conspiracies, such as far right or far left political oppression, government or alien manipulations and excess to ‘connections,’ as excuses for inaction.

Spending time on these emotionally demanding fantasies drains mental energies. It wastes not only precious time, but derails attention from personal well-being and career goals. The technological developments, financial complexities, and social changes demand meaningful decision making at every level. Maneuvering the stormy waters of change requires grooming our intellectual quotients. Occupation with gossip and unfounded fantasies leaves one stuck, while society is progressing at a breakneck pace. Being left behind by a progressing society creates increasing anxiety, which can easily culminate in depression, addictions and acts of desperation. We are the first generation to have the ability to analyze how our emotions influence our behavior. Certain aspects of our emotional inheritance can destroy the upcoming generation’s ability to succeed. The rigid mindset of the class system must be replaced by a strong belief in the ability of the self to initiate change.

Picture credit: Mother and child by Eva Deli