It's a question that has long fascinated and flummoxed those who study human behavior: From whence comes the impulse to dream? Are dreams generated from the brain's "top" -- the high-flying cortical structures that allow us to reason, perceive, act and remember? Or do they come from the brain's "bottom" -- the unheralded brainstem, which quietly oversees such basic bodily functions as respiration, heart rate, salivation and temperature control?

At stake is what to make of the funny, sexual, scary and just plain bizarre mental scenarios that play themselves out in our heads while we sleep. Are our subconsious fantasies coming up for a breath of air, as Sigmund Freud believed?

Is our brain consolidating lessons learned and pitching out unneeded data, as neuroscientists suggest? Or are dreams no more meaningful than a spontaneous run of erratic heartbeats, a hot flash, or the frisson we feel at the sight of an attractive passer-by?

A study published this week in the journal Brain suggests that the impulse to dream may be little more than a tickle sent up from the brainstem to the brain's sensory cortex.

The full dream experience -- the complex scenarios, the feelings of fear, delight or longing -- may require the further input of the brain's higher-order cortical areas, the new research suggests. But even people with grievous injury to the brain's prime motivational machinery are capable of dreams, the study found.

The latest research looked for sleep-time "mentation" -- thoughts, essentially -- in a small group of very unusual patients. These patients -- 13 in all -- had suffered damage within their brains' limbic system, the seat of our basic desires and motivations -- for sex, for food, for pleasurable sensations brought on by drugs and friendship and whatever else turns us on.

Despite having well-developed brains, complex technologies and centuries of scientific progress, the human species remains a fearful, superstitious lot. And what better day to revisit the nature of superstition than Friday the 13th?

Superstition, it seems, is one thing that binds all of humanity throughout history and across cultural divides. Anthropologist Claude Lévi-Strauss once wrote that superstitions and belief in magic "are so frequent and so widespread that we should ask ourselves if we are not confronted with a permanent and universal form of thought."

Even in the modern world, superstitions hold immense sway over people's daily lives. "Several surveys of Americans suggest that roughly half say they are at least slightly superstitious," said Stuart Vyse, professor of psychology at Connecticut College. "A 2007 Gallup poll found that 13 percent of Americans would be bothered by staying on the 13th floor of a hotel. Nine percent would be bothered enough to ask for a different room."

The root of superstition is a lack of control, according to Vyse, the author of Believing in Magic: The Psychology of Superstition (Oxford, 2013). "Generally, [superstition] is aimed at achieving greater control," Vyse told LiveScience. "When something important is at stake yet the outcome is uncertain, then superstitions are likely to be used to fill the gap and make us feel more confident."

Most of the time, we try to avoid inflicting pain on others - when we do hurt someone, we typically experience guilt, remorse, or other feelings of distress. But for some, cruelty can be pleasurable, even exciting. New research suggests that this kind of everyday sadism is real and more common than we might think.

Two studies led by psychological scientist Erin Buckels of the University of British Columbia revealed that people who score high on a measure of sadism seem to derive pleasure from behaviors that hurt others, and are even willing to expend extra effort to make someone else suffer.

The new findings are published in Psychological Science, a journal of the Association for Psychological Science.

"Some find it hard to reconcile sadism with the concept of 'normal' psychological functioning, but our findings show that sadistic tendencies among otherwise well-adjusted people must be acknowledged," says Buckels. "These people aren't necessarily serial killers or sexual deviants but they gain some emotional benefit in causing or simply observing others' suffering."

Based on their previous work on the "Dark Triad" of personality, Buckels and colleagues Delroy Paulhus of the University of British Columbia and Daniel Jones of the University of Texas El Paso surmised that sadism is a distinct aspect of personality that joins with three others - psychopathy, narcissism, and Machiavellianism - to form a "Dark Tetrad" of personality traits.

To test their hypothesis, they decided to examine everyday sadism under controlled laboratory conditions. They recruited 71 participants to take part in a study on "personality and tolerance for challenging jobs." Participants were asked to choose among several unpleasant tasks: killing bugs, helping the experimenter kill bugs, cleaning dirty toilets, or enduring pain from ice water.

Participants who chose bug killing were shown the bug-crunching machine: a modified coffee grinder that produced a distinct crunching sound so as to maximize the gruesomeness of the task. Nearby were cups containing live pill bugs, each cup labeled with the bug's name: Muffin, Ike, and Tootsie.

Researchers studying heroin addiction have discovered how the drug triggers a switch in an area of the brain associated with learning and memory, fuelling compulsive cravings for the opiate-class drug.

The work in finding the underlying molecular process by which opiate addiction develops in the brain was carried out by scientists at the University of Western Ontario in London, Ont.

Opiate addiction is largely controlled by the formation of powerful reward memories that link the pleasurable effects of opiates to environmental triggers, reinforcing dependence and relapse.

The team led by Dr. Steven Laviolette was able to identify how exposure to heroin induces a specific switch in a memory molecule in the basolateral amygdala.

During the early stages of opiate exposure, there is a specific molecular pathway in the amygdala that is responsible for the formation of those reward memories. The scientists call it the ERK (extracellular signal-related kinase) pathway.

Two new studies have revealed readily-detectable, early-warning signs of cognitive impairment.

One study from researchers at the University of California, Davis revealed that the degeneration of a small structure deep in the brain called the fornix provides early clues for the future onset of memory loss or dementia. The other study from the University of Toronto in Canada showed a new link between early-onset Parkinson's disease and a piece of DNA missing on chromosome 22.

In the UC Davis study, researchers recruited over 100 cognitively healthy people with an average age of 73. Participants underwent brain scans using magnetic resonance imaging (MRI) that revealed their brain volumes and integrity. The researchers also administered psychological tests and cognitive assessments to the participants to score their level of mental function. The study volunteers returned for MRIs and cognitive assessment at about one-year intervals.

At the beginning of the study, none of the participants showed signs of mental decline. Over time, about 20 percent began to exhibit symptoms that would eventually lead to a diagnosis of mild cognitive impairment (MCI) or, in a few cases, Alzheimer's disease.

The researchers found that variables related to the fornix, an organ that ferries messages to and from the hippocampus, are measurable brain factors that precede cognitive deterioration, according to their report in the JAMA journal Neurology.

In the film Eternal Sunshine of the Spotless Mind, Jim Carrey played a man who had his brain scrubbed of painful memories - only to have them eventually come back to haunt him.

While the selective deletion of memories may sound like science fiction, neuroscientists from The Scripps Research Institute have demonstrated just that in mice and rats, according to their report in the journal Biological Psychiatry.

The Scripps researchers said the technique might be useful for treating people suffering from post-traumatic stress disorder (PTSD) or battling a drug addiction.

"Our memories make us who we are, but some of these memories can make life very difficult," said study leader Courtney Miller, a TSRI assistant professor of neuroscience. "Not unlike in the movie Eternal Sunshine of the Spotless Mind, we're looking for strategies to selectively eliminate evidence of past experiences related to drug abuse or a traumatic event. Our study shows we can do just that in mice - wipe out deeply engrained drug-related memories without harming other memories."

When a memory is created, changes occur to the structure of dendritic spines found on nerve cells. These small, bulb-like structures receive electrochemical transmissions from other neuronsn and structural changes to them normally occur via a protein called actin.

The body's defense cells engage the brain in an intricate dialogue that may help raise IQ.

After spending a few days in bed with the flu, you may have felt a bit stupid. It is a common sensation, that your sickness is slowing down your brain. At first blush, though, it doesn't make much sense. For one thing, flu viruses infect the lining of the airways, not the neurons in our brains. For another, the brain is walled off from the rest of the body by a series of microscopic defenses collectively known as the blood-brain barrier. It blocks most viruses and bacteria while allowing essential molecules like glucose to slip through. What ails the body, in other words, shouldn't interfere with our thinking.

But over the past decade, Jonathan Kipnis, a neuroimmunologist in the University of Virginia School of Medicine's department of neuroscience, has discovered a possible link, a modern twist on the age-old notion of the body-mind connection. His research suggests that the immune system engages the brain in an intricate dialogue that can influence our thought processes, coaxing our brains to work at their best.

Kipnis got the idea of an immunity-intelligence link while earning his Ph.D. at the Weizmann Institute of Science in Israel. His adviser, Michal Schwartz, was performing experiments to understand how the brain repairs itself after an injury. She found that the brain depends on a type of immune cell known as the T cell, which normally kills infected cells or leads other immune cells in a campaign against foreign invaders. Her research suggested that T cells can also send signals that activate the brain's resident immune cells, microglia and blood-borne macrophages, telling them to protect the injured neurons from toxins released by the injury.

Researchers have discovered a sixth sense mapped out in the human brain: the ability to compare the amount of any given object, whether it be the number of people in a concert hall or jelly beans in a glass jar.

Called "numerosity," researchers have long suspected that this sense existed, but were unable to detect its presence within the brain. In particular, researchers were unable to identify a topographical map in which neurons related to numerosity assessment were laid out in such a way that those most closely related were able to interact over the shortest possible distance -- a phenomenon characteristic of the primary senses.

A new paper published in the journal Science changes all of that.

Led by Utrecht University's Benjamin Harvey, the study included eight participants, each of whom were asked to look at patterns of dots whose numbers changed over time.

Meanwhile, the scientists analyzed the neural response properties in a part of the brain linked to numerosity using high-field functional magnetic resonance imaging.

© Unknown

TAU researchers use a zoological method to classify symptoms of OCD and schizophrenia in humans.

Because animals can't talk, researchers need to study their behavior patterns to make sense of their activities. Now researchers at Tel Aviv University are using these zoological methods to study people with serious mental disorders.

Prof. David Eilam of TAU's Zoology Department at The George S. Wise Faculty of Life Sciences recorded patients with obsessive-compulsive disorder and "schizo-OCD" - which combines symptoms of schizophrenia and OCD - as they performed basic tasks. By analyzing the patients' movements, they were able to identify similarities and differences between two frequently confused disorders.

Published in the journal CNS Spectrums, the research represents a step toward resolving a longstanding question about the nature of schizo-OCD: Is it a combination of OCD and schizophrenia, or a variation of just one of the disorders?

Many American parents yell or shout at their teenagers. A new longitudinal study has found that using such harsh verbal discipline in early adolescence can be harmful to teens later. Instead of minimizing teens' problematic behavior, harsh verbal discipline may actually aggravate it.

The study, from researchers at the University of Pittsburgh and the University of Michigan, appears in the journal Child Development.

Harsh verbal discipline happens when parents use psychological force to cause a child to experience emotional pain or discomfort in an effort to correct or control behavior. It can vary in severity from yelling and shouting at a child to insulting and using words to humiliate. Many parents shift from physical to verbal discipline as their children enter adolescence, and harsh verbal discipline is not uncommon. A nationally representative survey found that about 90 percent of American parents reported one or more instances of using harsh verbal discipline with children of all ages; the rate of the more severe forms of harsh verbal discipline (swearing and cursing, calling names) directed at teens was 50 percent.

Few studies have looked at harsh verbal discipline in adolescence. This study found that when parents use it in early adolescence, teens suffer detrimental outcomes later. The children of mothers and fathers who used harsh verbal discipline when they were 13 suffered more depressive symptoms between ages 13 and 14 than their peers who weren't disciplined in this way; they were also more likely to have conduct problems such as misbehaving at school, lying to parents, stealing, or fighting.