Virtual humans inspire patients to open up

When we feel down and find ourselves at the doctor’s office for help, the best person to get us to open up about our problems isn’t a person at all. It’s a computer.

A new USC study suggests that patients are more willing to disclose personal information to virtual humans than actual ones, in large part because computers lack the proclivity to look down on people the way another human might.

The research, which was funded by the Defense Advanced Research Projects Agency and the U.S. Army, is promising for people suffering from post-traumatic stress and other mental anguish, said Gale Lucas, a social psychologist at USC’s Institute for Creative Technologies, who led the study. In intake interviews, people were more honest about their symptoms, no matter how potentially embarrassing, when they believed that a human observer wasn’t in on the conversation.

“In any given topic, there’s a difference between what a person is willing to admit in person versus anonymously,” Lucas said.

The study, which will be published in the journal Computers in Human Behavior, provides the first empirical evidence that virtual humans can increase a patient’s willingness to disclose personal information in a clinical setting, researchers said. It also presents compelling reasons for doctors to start using virtual humans as medical screeners. The honest answers acquired by a virtual human could help doctors diagnose and treat their patients more appropriately.

The recruitment process

Researchers recruited 239 adults through Craigslist to participate in the study. The adults, whose ages ranged from 18 to 65, were invited to a laboratory to interact with a virtual human as if they were being admitted to a clinic or hospital.

Subjects were interviewed as part of an evaluation of SimSensei, a virtual human application that can be used to identify signals of depression and other mental health issues through real-time sensing and recognition of nonverbal behaviors. It is a research project designed to assess the potential of such technology and is based on more than 10 years of virtual human research and development at ICT.

Some participants were told the virtual human’s responses were fully automated, others were told that the responses were remotely controlled, puppet-like, by a human observer in another room. In reality, all participants were randomly assigned a fully or semi-automated virtual human, regardless of what they were told, and their video interviews were later analyzed by a (human) researcher.

The mere belief that participants were interacting with only a computer made them more open and honest, researchers found, even when the virtual human asked personal questions such as, “What’s something you feel guilty about?” or “Tell me about an event, or something that you wish you could erase from your memory.”

In addition, video analysis of the study subjects’ facial expressions showed that they were also more likely to show more intense signs of sadness — perhaps the most vulnerable of expressions — when they thought only pixels were present.

Opening up to a virtual human

One participant who thought the virtual human was automated said the experience was “way better than talking to a person. I don’t really feel comfortable talking about personal stuff to other people.”

In contrast, a participant who thought the conversation was being observed told researchers, “I wish you hadn’t told me that other people were in the other room listening in. It was weird, like, I don’t even know these people. I would have said a lot more stuff if they weren’t there.”

The virtual human named Ellie opened the conversation with questions such as “Where are you from originally?” and incorporated feedback (“I’m sorry to hear that”) and empathetic listening through facial expressions and nodding. Secondly, “her” virtual nature gave participants a sense of anonymity, making them more willing to disclose personal information in a private setting without fear of criticism.

“We know that developing a rapport and feeling free of judgment are two important factors that affect a person’s willingness to disclose personal information,” said co-author Jonathan Gratch, director of virtual humans research at ICT and a professor in USC’s Department of Computer Science. “The virtual character delivered on both these fronts and that is what makes this a particularly valuable tool for obtaining information people might feel sensitive about sharing.”

The researchers were careful to emphasize that the virtual human could supplement — not replace — trained clinicians. Still, the implications of the findings are plentiful both in terms of reducing costs and improving care, and several are being explored in projects being developed at ICT, including virtual humans to help detect signs of depression, provide screening services for patients in remote areas or act as role-playing partners for training health professionals.

In an age where people are increasingly interacting with computers over real people for everything from banking to grocery shopping, the researchers hope that opening up to a virtual character will open the door for people to get the care they need in a variety of health care settings as well.

(Image caption: On these images, the cerebral activation detected by ultrasound imaging is shown in red. During odor presentation, specific areas are activated in the olfactory bulb but not in the piriform cortex. Credit: © Mickael Tanter / Hirac Gurden)

Ultrasound tracks odor representation in the brain

A new ultrasound imaging technique has provided the first ever in vivo visualization of activity in the piriform cortex of rats during odor perception. This deep-seated brain structure plays an important role in olfaction, and was inaccessible to functional imaging until now. This work also sheds new light on the still poorly known functioning of the olfactory system, and notably how information is processed in the brain. This study is the result of a collaboration between the team led by Mickael Tanter at the Institut Langevin (CNRS/INSERM/ESPCI ParisTech/UPMC/Université Paris Diderot) and that led by Hirac Gurden in the Laboratoire Imagerie et Modélisation en Neurobiologie et Cancérologie (CNRS/Université Paris-Sud/Université Paris Diderot). Their findings are published in NeuroImage.

How can the perception of the senses help represent the external environment? How, for example, does the brain process food-or perfume-related olfactory data? Although the organization of the olfactory system is well known - it is similar in organisms ranging from insects to mammals - its functioning remains unclear. To answer these questions, the scientists focused on the two brain structures that act as major olfactory relays: the olfactory bulb and the piriform cortex. In the rat, the olfactory bulb is located between the eyes, just behind the nasal bone. The piriform cortex, meanwhile, is deep-seated in the brain of rodents, which made it impossible to obtain any functional images in a living animal until now.

Yet the neurofunctional ultrasound imaging technique developed by Mickael Tanter’s team, called fUS(functional Ultrasound), allows the monitoring of neuronal activity in the piriform cortex. It is based on the transmission of ultrasonic plane waves into the brain tissue. After data processing, the echoes returned by the structures crossed by these waves can provide images with unequalled spatial and temporal resolution: 80 micrometers and a few tens of milliseconds. The contrast on these images is due to variations in the brain’s blood flow. Indeed, the activity of nerve cells requires an input of energy: it is therefore coupled to an influx of blood into the zone concerned. By recording volume variations in the blood vessels irrigating the different brain structures, it is there fore possible to determine the location of activated neurons.

Several imaging techniques, such as MRI, are already based on the link between blood volume and neuronal activity. But fUS offers advantages in terms of cost, ease of use and resolution. Furthermore, it provides easier access to the deepest structures that are often located several centimeters beneath the cranium.

The recordings performed by Hirac Gurden’s team using this technique made it possible to observe the spatial distribution of activity within the olfactory bulb. When an odor was perceived, blood volume increased in clearly defined areas: each odor thus corresponded to a specific pattern of activated neurons. In addition to these findings, and for the first time, the images revealed an absence of spatial distribution in the piriform cortex. At this level, two different odors triggered the same activation throughout the region.

The cellular mechanisms responsible for the disappearance of a spatial signature are not yet clearly defined, but these findings lead to the formulation of several hypotheses. The piriform cortex could be a structure that serves not only to process olfactory stimuli but rather to integrate and memorize different types of data. By making abstraction of the strict odor-induced patterns, it would be possible to make associations and achieve a global concept. For example, based on the perception of the hundreds of odorant molecules found in coffee, the piriform cortex would be able to recognize a single odor, that of
coffee.

This work opens new perspectives for both imaging and neurobiology. The researchers will now be focusing on the effects of learning on cortical activity in order to elucidate its role and the specificities of the olfactory system.

Blame it on the astrocytes

In the brains of all vertebrates, information is transmitted through synapses, a mechanism that allows an electric or chemical signal to be passed from one brain cell to another. Chemical synapses, which are the most abundant type of synapse, can be either excitatory or inhibitory. Synapse formation is crucial for learning, memory, perception and cognition, and the balance between excitatory and inhibitory synapses critical for brain function. For instance, every time we learn something, the new information is transformed into memory through synaptic plasticity, a process in which synapses are strengthened and become more responsive to different stimuli or environmental cues. Synapses may change their shape or function in a matter of seconds or over an entire lifetime. In humans, a number of disorders are associated with dysfunctional synapses, including autism, epilepsy, substance abuse and depression.

Astrocytes, named for their star-like shape, are ubiquitous brain cells known for regulating excitatory synapse formation through cells. Recent studies have shown that astrocytes also play a role in forming inhibitory synapses, but the key players and underlying mechanisms have remained unknown until now.

A new study just published in the journal Glia and available online on July 11th, details the newly discovered mechanism by which astrocytes are involved in inhibitory synapse formation and presents strong evidence that Transforming Growth Factor Beta 1 (TGF β1), a protein produced by many cell types (including astrocytes) is a key player in this process. The team led by Flávia Gomes of the Rio de Janeiro Institute of Biomedical Sciences at the Federal University of Rio de Janeiro investigated the process in both mouse and human tissues, first in test tubes, then in living brain cells.

Previous evidence has shown that TGF β1, a molecule associated with essential functions in nervous system development and repair, modulates other components responsible for normal brain function. In this study, the authors were able to show that TGF β1 triggers N-methyl-D-aspartate receptor (NMDA), a molecule controlling memory formation and maintenance through synaptic plasticity. In the study, the group also shows that TGF β1-induction of inhibitory synapses depends on activation of another molecule - Ca2+/calmodulin-dependent protein kinase II (CaMK2)-, which works as a mediator for learning and memory. “Our study is the first to associate this complex pathway of molecules, of which TGF β1 seems to be a key player, to astrocytes’ ability to modulate inhibitory synapses”, says Flávia Gomes.

The idea that the balance between excitatory and inhibitory inputs depends on astrocyte signals gains strong support with this new study and suggests a pivotal role for astrocytes in the development of neurological disorders involving impaired inhibitory synapse transmission. Knowing the players and mechanisms underlying inhibitory synapses may improve our understanding of synaptic plasticity and cognitive processes and may help develop new drugs for treating these diseases.

(Image credit)

Brain activity in sex addiction mirrors that of drug addiction

Pornography triggers brain activity in people with compulsive sexual behaviour – known commonly as sex addiction – similar to that triggered by drugs in the brains of drug addicts, according to a University of Cambridge study published in the journal PLOS ONE. However, the researchers caution that this does not necessarily mean that pornography itself is addictive.

Although precise estimates are unknown, previous studies have suggested that as many as one in 25 adults is affected by compulsive sexual behaviour, an obsession with sexual thoughts, feelings or behaviour which they are unable to control. This can have an impact on a person’s personal life and work, leading to significant distress and feelings of shame. Excessive use of pornography is one of the main features identified in many people with compulsive sexual behaviour. However, there is currently no formally accepted definition of diagnosing the condition.

In a study funded by the Wellcome Trust, researchers from the Department of Psychiatry at the University of Cambridge looked at brain activity in nineteen male patients affected by compulsive sexual behaviour and compared them to the same number of healthy volunteers. The patients started watching pornography at earlier ages and in higher proportions relative to the healthy volunteers.

“The patients in our trial were all people who had substantial difficulties controlling their sexual behaviour and this was having significant consequences for them, affecting their lives and relationships,” explains Dr Valerie Voon, a Wellcome Trust Intermediate Clinical Fellow at the University of Cambridge. “In many ways, they show similarities in their behaviour to patients with drug addictions. We wanted to see if these similarities were reflected in brain activity, too.”

The study participants were shown a series of short videos featuring either sexually explicit content or sports whilst their brain activity was monitored using functional magnetic resonance imaging (fMRI), which uses a blood oxygen level dependent (BOLD) signal to measure brain activity.

The researchers found that three regions in particular were more active in the brains of the people with compulsive sexual behaviour compared with the healthy volunteers. Significantly, these regions – the ventral striatum, dorsal anterior cingulate and amygdala – were regions that are also particularly activated in drug addicts when shown drug stimuli. The ventral striatum is involved in processing reward and motivation, whilst the dorsal anterior cingulate is implicated in anticipating rewards and drug craving. The amygdala is involved in processing the significance of events and emotions.

The researchers also asked the participants to rate the level of sexual desire that they felt whilst watching the videos, and how much they liked the videos. Drug addicts are thought to be driven to seek their drug because they want – rather than enjoy – it. This abnormal process is known as incentive motivation, a compelling theory in addiction disorders.

As anticipated, patients with compulsive sexual behaviour showed higher levels of desire towards the sexually explicit videos, but did not necessarily rate them higher on liking scores. In the patients, desire was also correlated with higher interactions between regions within the network identified – with greater cross-talk between the dorsal cingulate, ventral striatum and amygdala – for explicit compared to sports videos.

Dr Voon and colleagues also found a correlation between brain activity and age – the younger the patient, the greater the level of activity in the ventral striatum in response to pornography. Importantly, this association was strongest in individuals with compulsive sexual behaviour. The frontal control regions of the brain – essentially, the ‘brakes’ on our compulsivity – continue to develop into the mid-twenties and this imbalance may account for greater impulsivity and risk taking behaviours in younger people. The age-related findings in individuals with compulsive sexual behaviours suggest that the ventral striatum may be important in developmental aspects of compulsive sexual behaviours in a similar fashion as it is in drug addictions, although direct testing of this possibility is needed.

“There are clear differences in brain activity between patients who have compulsive sexual behaviour and healthy volunteers. These differences mirror those of drug addicts,” adds Dr Voon. “Whilst these findings are interesting, it’s important to note, however, that they could not be used to diagnose the condition. Nor does our research necessarily provide evidence that these individuals are addicted to porn – or that porn is inherently addictive. Much more research is required to understand this relationship between compulsive sexual behaviour and drug addiction.”

Dr John Williams, Head of Neuroscience and Mental Health at the Wellcome Trust, says: “Compulsive behaviours, including watching porn to excess, over-eating and gambling, are increasingly common. This study takes us a step further to finding out why we carry on repeating behaviours that we know are potentially damaging to us. Whether we are tackling sex addiction, substance abuse or eating disorders, knowing how best, and when, to intervene in order to break the cycle is an important goal of this research.”

Understanding Consciousness

Why does a relentless stream of subjective experiences normally fill your mind? Maybe that’s just one of those mysteries that will always elude us. 

Yet, research from Northwestern University suggests that consciousness lies well within the realm of scientific inquiry — as impossible as that may currently seem. Although scientists have yet to agree on an objective measure to index consciousness, progress has been made with this agenda in several labs around the world.

“The debate about the neural basis of consciousness rages because there is no widely accepted theory about what happens in the brain to make consciousness possible,” said Ken Paller, professor of psychology in the Weinberg College of Arts and Sciences and director of the Cognitive Neuroscience Program at Northwestern.

“Scientists and others acknowledge that damage to the brain can lead to systematic changes in consciousness. Yet, we don’t know exactly what differentiates brain activity associated with conscious experience from brain activity that is instead associated with mental activity that remains unconscious,” he said.

In a new article, Paller and Satoru Suzuki, also professor of psychology at Northwestern, point out flawed assumptions about consciousness to suggest that a wide range of scientific perspectives can offer useful clues about consciousness.

“It’s normal to think that if you attentively inspect something you must be aware of it and that analyzing it to a high level would necessitate consciousness,” Suzuki noted. “Results from experiments on perception belie these assumptions.

“Likewise, it feels like we can freely decide at a precise moment, when actually the process of deciding begins earlier, via neurocognitive processing that does not enter awareness,” he said. 

The authors write that unconscious processing can influence our conscious decisions in ways we never suspect.

If these and other similar assumptions are incorrect, the researchers state in their article, then mistaken reasoning might be behind arguments for taking the science of consciousness off the table. 

“Neuroscientists sometimes argue that we must focus on understanding other aspects of brain function, because consciousness is never going to be understood,” Paller said. “On the other hand, many neuroscientists are actively engaged in probing the neural basis of consciousness, and, in many ways, this is less of a taboo area of research than it used to be.”

Experimental evidence has supported some theories about consciousness that appeal to specific types of neural communication, which can be described in neural terms or more abstractly in computational terms. Further theoretical advances can be expected if specific measures of neural activity can be brought to bear on these ideas.

Paller and Suzuki both conduct research that touches on consciousness. Suzuki studies perception, and Paller studies memory. They said it was important for them to write the article to counter the view that it is hopeless to ever make progress through scientific research on this topic.

They outlined recent advances that provide reason to be optimistic about future scientific inquiries into consciousness and about the benefits that this knowledge could bring for society.

“For example, continuing research on the brain basis of consciousness could inform our concerns about human rights, help us explain and treat diseases that impinge on consciousness, and help us perpetuate environments and technologies that optimally contribute to the well being of individuals and of our society,” the authors wrote.

They conclude that research on human consciousness belongs within the purview of science, despite philosophical or religious arguments to the contrary.

Their paper, “The Source of Consciousness,” has been published online in the journal Trends in Cognitive Sciences.

(Image: Shutterstock)

New research: teaching the brain to reduce pain

People can be conditioned to feel less pain when they hear a neutral sound, new research from the University of Luxembourg has found. This lends weight to the idea that we can learn to use mind-over-matter to beat pain. The scientific article was published recently in the online journal “PLOS One”.

Scientists have known for many years that on-going pain in one part of the body is reduced when a new pain is inflicted to another part of the body. This pain blocking is a physiological reaction by the nervous system to help the body deal with a potentially more relevant novel threat.

To explore this “pain inhibits pain” phenomenon, painful electric pulses were first administered to a subject’s foot (first pain) and the resulting pain intensity was then measured. Then the subject was asked to put their hand in a bucket of ice water (novel stimulus causing pain reduction), and as they did so, a telephone ringtone sounded in headphones. After this procedure had been repeated several times, it was observed that the pain felt from the electrical stimulation was reduced simply when the ring tone sounded.

The brain had been conditioned to the ringtone being a signal to trigger the body’s physical pain blocking mechanism. The people being tested not only felt significantly less pain, but there were also fewer objective signs of pain, such as activity in the muscles used in the facial expression of pain (frowning). In total, 32 people were tested.

“We have shown that just as the physiological reaction of saliva secretion was provoked in Pavlov’s dogs by the ringing of a bell, an analogous effect occurs regarding the ability to mask pain in humans,” said Fernand Anton, Professor of Biological Psychology at the University of Luxembourg. “Conversely, similar learning effects may be involved in the enhancement and maintenance of pain in some patients,” added Raymonde Scheuren, lead researcher in this study.