Some advice my dad gave me: “If your wife says she never dreams about sex with another man, she’s lying. If she says she never dreams about sex with another woman, she’s lying then too.”

He may have been on to something. It turns out everyone, men and women alike, dream about sex.

In a detailed study that served to investigate the actual nature and content of sexual dreams across a large sample of dream reports from men and women, approximately eight percent of everyday dream reports from both genders contain some form of sexual-related activity.

The percentage of women that reported such dreams can be due to the fact that either women actually experience more sexual dreams now than they did 40 years ago, or that they now feel more comfortable reporting such dreams due to changing social roles and attitudes, or both.

The study, authored by Antonio Zadra, PhD, of the Universite de Montreal, focused on over 3,500 home dream reports collected from men and women. Sexual intercourse was the most common type of sexual dream content, followed by sexual propositions, kissing, fantasies and masturbation.

The study found that both men and women reported experiencing an orgasm in about four percent of their sexual dreams. Orgasms were described as being experienced by another dream character in four percent of the women’s sexual dreams, but in none of the male dream reports. Current or past partners were identified in 20 percent of women’s sexual dreams, compared to 14 percent for men, and public figures were twice as likely to be the object of women’s sexual dream content. Multiple sex partners were reported twice as frequently in men’s sexual dreams.

“Observed gender differences may be indicative of different waking needs, experiences, desires and attitudes with respect to sexuality,” said Zadra. “This is consistent with the continuity hypothesis of dreaming which postulates that the content of everyday dreams reflects the dreamer’s waking states and concerns – that is, that dream and waking thought contents are continuous.”

Source: AASM

The long supposed connection between mind and music has been further demonstrated by an international collaboration of physicists led by Simone Bianco and Paolo Grigolini at the Center for Nonlinear Science at the University of North Texas. A statistical analysis reveals a remarkable similarity between the distributions produced by music compositions and brain activity.

Brain activity was monitored through an electroencephalograph (EEG), which records electrical signals on the surface of the brain. The musical compositions were analyzed based on the melody, harmony, rhythm, pitch, and timber among other factors.

Researchers mapped brain activity and the compositions by regions of similarity punctuated by jumps where a significant change occurred. The data illustrated the similarity between patterns of electrical signals in the brain and of musical compositions.

In addition, the team determined a complexity index for the compositions and brain function, a number to describe the intricacy of either the musical patterns or electrical signals. The complexity indices for both patterns were less than two. This suggests that both the brain and the composition are self-organized, but in the case of the composition, it probably reflects the self-organized mind of the composer. The interpretation of the complexity index remains a question for further research.

In future experiments, researchers will monitor the brain activity of participants who are listening to music. This study will assess whether the complexity of a participant¿s brain activity is affected by the complexity of the composition. In addition, they will seek “fits” where the complexity of the music resembles the brain activity of the listener. If the physcists’ hypothesis is correct, the fit between a composition and your brain activity helps determine your musical preferences.

Source: Brain, Music and non-Poisson Renewal Processes

Human interaction and stimulation enhance chimpanzees’ cognitive abilities, according to new research from the Chimpanzee Cognition Center at The Ohio State University. The study (1) is the first to demonstrate that raising chimpanzees in a human cultural environment enhances their cognitive abilities, as measured by their ability to understand how tools work.

The scientists compared three groups of chimpanzees: one with a history of long-term stable, social interaction with humans (‘enculturated’); a group raised in a sanctuary setting, with only caretaker contact with humans (‘semi-enculturated’); and another group raised under more austere captive conditions (laboratory chimpanzees). The experiments looked at how the chimpanzees used rakes in order to retrieve a fruit yoghurt reward. The overall study examined not only whether the chimpanzees understood the properties of the tool, but also whether they understood the reasons why the tool worked.

The researchers gave the animals access to small rakes with either a rigid wooden head or a flimsy fabric head. Both enculturated and semi-enculturated chimpanzees correctly chose the rigid rake which enabled them to obtain the reward, indicating that both of these groups understood the physical properties of the two different rakes.

The researchers then presented the same two groups with two identical ‘hybrid’ rakes. Each rake head had a rigid side made of wood (functional) and another side made of flimsy cloth (non-functional). The reward was placed in front of the rigid side of one rake, and in front of the flimsy side of the second rake. The animals who picked the rake with the food reward on the rigid side demonstrated that they understood the causal principles behind the functionality of the rake.

The enculturated chimpanzees successfully selected the functional rake, while the sanctuary chimpanzees chose randomly between the two hybrid tools. The captive laboratory chimpanzees failed both tests, as demonstrated in previously published work (2).

According to Dr. Sarah Boysen, who led the study, “We think our findings mean that the conditions under which chimpanzees are raised, housed, and maintained have long-term effects on their cognitive development, and offer direct comparisons with early experience, issues of attachment, and preschool education for human infants and children,”

The authors conclude that the differences in performance between the three groups are directly attributable to the significant effect of level of enculturation. They add that “enculturated chimpanzees may be better at learning within a highly social, interactive context because they have heightened attention to the actions of others.”

1. Furlong EE, Boose KJ, Boysen ST (2007). Raking it in: the impact of enculturation on chimpanzee tool use. Animal Cognition DOI 10.1007/s10071-007-0091-6

2. Povinelli DJ (2000). Folk physics for apes: the chimpanzee’s theory of how the world works. Oxford University Press, New York.

Source: Animal Cognition

A newly discovered interplay of cells in one of the brain’s memory centers sheds light on how you recall your grocery list, where you laid your keys, and a host of important but fleeting daily tasks.

Scientists at Weill Cornell Medical College say their experiments with common goldfish are uncovering the secrets of a form of short-term recall known as “working memory.”

“We’ve now identified a mechanism that can organize the activity of groups of cells involved in this important form of recall,” says lead researcher Dr. Emre Aksay, assistant professor of computational neuroscience in the HRH Prince Alwaleed Bin Talal Bin Abdulaziz Al-Saud Institute for Computational Biomedicine at Weill Cornell Medical College in New York City.

“Furthermore, because deficits in working memory are often a precursor of schizophrenia, drugs that target this mechanism might someday help fight that debilitating disease,” he says.

The findings have been published in Nature Neuroscience.

Humans rely on their working memory every day to keep track of faces and names, tasks at school or in the workplace, and other important bits of information. “This process is distinct, neurologically speaking, from the storage and retrieval of longer-term memories,” explains Dr. Aksay, who is also assistant professor of physiology and biophysics at Weill Cornell.

Experts in labs around the world have developed theories as to how this process works. “Its basis lies in the ability of specific neurons to maintain a level of activity in the absence of input — a persistent firing rate — that’s finely coordinated across related groups of cells,” Dr. Aksay says.

But how do these brain cells communicate which each other to coordinate this activity”

To find out, Dr. Aksay, along with colleagues Dr. David Tank of Princeton University, and Dr. Mark Goldman of Wellesley College, turned to the common goldfish.

“It’s really quite difficult to test the function of individual brain cells in primates and higher animals during behavior, but the goldfish’s memory centers are much more accessible to research,” Dr. Aksay explains. “We looked specifically at the fishes’ oculomotor system — the neural circuitry that directs the fish to shift its eyes left or right based on stimuli in the local environment.” Because stimuli can be ever-changing and fleeting, the fish relies on its short-term memory to help guide these eye movements.

Two groups of cells are involved in this oculomotor memory, one in each half of the brain. Each group contains two types of neurons — inhibitory cells and excitatory cells, and it is the inhibitory neurons that allow the two groups to interact. “In our experiments, we used pharmacologic means to interrupt either excitatory or inhibitory pathways, and then we watched what happened to persistent firing,” Dr. Aksay says.

When the excitatory pathways were dampened, the persistence was impaired — suggesting that excitation is essential to the sustained firing that working memory requires.

“The real surprise came when we turned off many of the inhibitory pathways,” Dr. Aksay says. In that case, persistent firing remained, but was often present at inappropriate times.

“It appears that the inhibitory cells are not key or even required to generate persistent firing,” the researcher says. “Instead, they send a message from one group to the other that helps coordinate two sides: the role of inhibition in this system is to make sure that only one group is generating persistent activity at a given time. In this way, the goldfish doesn’t get a mixed signal telling it to move its eyes in both directions at once.”

This new finding has big implications for our understanding of the neural processes underlying working memory and the instantaneous decision-making that goes on based on that knowledge.

It might also have broader applications for psychiatric illness, Dr. Aksay notes.

“Many schizophrenic individuals, for example, show severe deficits in working memory, and children with working memory problems are at heightened risk of developing schizophrenia as adults,” he says. Dysfunction in key inhibitory pathways that link brain cells has long been associated with these problems.

“These findings suggest that it is necessary to address not only deficits in excitatory pathways that lead to a lack of persistent firing but also dysfunction in inhibitory pathways that lead to a lack of coordination among groups of cells,” Dr. Aksay explains. “This strategy could provide improved treatment options for people with schizophrenia.”

Source: New York- Presbyterian Hospital/Weill Cornell Medical Center/Weill Cornell Medical College