Posts tagged emotion
Posts tagged emotion
Leading expert in neurology Michael Trimble, British professor at the Institute of Neurology in London, says that there must have been a time in human evolution when tears represented something greater than their simple function of lubricating the eye.
In his new book, Why Humans Like To Cry, Trimble tries to explain the mystery of why humans are the only species in the animal kingdom to shed tears in response to an emotional state. In his book, Trimble examines the physiology and the evolutionary past of emotional crying.
Trimble explains that biologically, tears are important to protect the eye. They keep the eyeball moist, flush out irritants and contain certain proteins and substances that keep the eye healthy and fight infections. He explains that in every other animal on planet Earth, tears seem to only serve these biological purposes.
However, in humans, crying or sobbing, bawling or weeping seems to serve another purpose: communicating emotion. Humans cry for many reasons- out of joy, grief, anger, relief and a variety of other emotions. However, our tears are most frequently shed out of sadness. Trimble said that it was this specific communicative nature of human crying that piqued his interest.
“Humans cry for many reasons,” he told Scientific American. “But crying for emotional reasons and crying in response to aesthetic experiences are unique to us.”
“The former is most associated with loss and bereavement, and the art forms that are most associated with tears are music, literature and poetry,” he said. “There are very few people who cry looking at paintings, sculptures or lovely buildings. But we also have tears of joy the associated feelings of which last a shorter time than crying in the other circumstances.”
The Knowing Nose: Chemosignals Communicate Human Emotions
Many animal species transmit information via chemical signals, but the extent to which these chemosignals play a role in human communication is unclear. In a new study published in Psychological Science, a journal of the Association for Psychological Science, researcher Gün Semin and colleagues from Utrecht University in the Netherlands investigate whether we humans might actually be able to communicate our emotional states to each other through chemical signals.
Existing research suggests that emotional expressions are multi-taskers, serving more than one function. Fear signals, for example, not only help to warn others about environmental danger, they are also associated with behaviors that confer a survival advantage through sensory acquisition. Research has shown that taking on a fearful expression (i.e., opening the eyes) leads us to breathe in more through our noses, enhances our perception, and accelerates our eye movements so that we can spot potentially dangerous targets more quickly. Disgust signals, on the other hand, warn others to avoid potentially noxious chemicals and are associated with sensory rejection, causing us to lower our eyebrows and wrinkle our noses.
Semin and colleagues wanted to build on this research to examine the role of chemosignals in social communication. They hypothesized that chemicals in bodily secretions, such as sweat, would activate similar processes in both the sender and receiver, establishing an emotional synchrony of sorts. Specifically, people who inhaled chemosignals associated with fear would themselves make a fear expression and show signs of sensory acquisition, while people who inhaled chemosignals associated with disgust would make an expression of disgust and show signs of sensory rejection.
Researchers from UCL have found that lonely people have less grey matter in a part of the brain associated with decoding eye gaze and other social cues.
Published in the journal of Current Biology, the study also suggests that through training people might be able to improve their social perception and become less lonely.
“What we’ve found is the neurobiological basis for loneliness,” said lead author Dr Ryota Kanai (UCL Institute of Cognitive Neuroscience). “Before conducting the research we might have expected to find a link between lonely people and the part of the brain related to emotions and anxiety, but instead we found a link between loneliness and the amount of grey matter in the part of the brain involved in basic social perception.”
To see how differences in loneliness might be reflected in the structure of the brain regions associated with social processes, the team scanned the brains of 108 healthy adults and gave them a number of different tests. Loneliness was self-reported and measured using a UCLA loneliness scale questionnaire.
When looking at full brain scans they saw that lonely individuals have less greymatter in the left posterior superior temporal sulcus (pSTS)—an area implicated in basic social perception, confirming that loneliness was associated with difficulty in processing social cues.
“The pSTS plays a really important role in social perception, as it’s the initial step of understanding other people,” said Dr Kanai. “Therefore the fact that lonely people have less grey matter in their pSTS is likely to be the reason why they have poorer perception skills.”
In order to gauge social perception, participants were presented with three different faces on a screen and asked to judge which face had misaligned eyes and whether they were looking either right or left. Lonely people found it much harder to identify which way the eyes were looking, confirming the link between loneliness, the size of the pSTS and the perception of eye gaze.
“From the study we can’t tell if loneliness is something hardwired or environmental,” said co-author Dr Bahador Bahrami (UCL Institute of Cognitive Neuroscience). “But one possibility is that people who are poor at reading social cues may experience difficulty in developing social relationships, leading to social isolation and loneliness.”
One way to counter this loneliness could be through social perception training with a smartphone app.
“The idea of training is one way to address this issue, as by maybe using a smartphone app to improve people’s basic social perception such as eye gaze, hopefully we can help them to lead less lonely lives,” said Dr Kanai.
Researchers Identify Area of the Brain That Processes Empathy
An international team led by researchers at Mount Sinai School of Medicine in New York has for the first time shown that one area of the brain, called the anterior insular cortex, is the activity center of human empathy, whereas other areas of the brain are not. The study is published in the September 2012 issue of the journal Brain.
Empathy, the ability to perceive and share another person’s emotional state, has been described by philosophers and psychologists for centuries. In the past decade, however, scientists have used powerful functional MRI imaging to identify several regions in the brain that are associated with empathy for pain. This most recent study, however, firmly establishes that the anterior insular cortex is where the feeling of empathy originates.
“Now that we know the specific brain mechanisms associated with empathy, we can translate these findings into disease categories and learn why these empathic responses are deficient in neuropsychiatric illnesses, such as autism,” said Patrick R. Hof, MD, Regenstreif Professor and Vice-Chair, Department of Neuroscience at Mount Sinai, a co-author of the study. “This will help direct neuropathologic investigations aiming to define the specific abnormalities in identifiable neuronal circuits in these conditions, bringing us one step closer to developing better models and eventually preventive or protective strategies.”
How fear skews our spatial perception
That snake heading towards you may be further away than it appears. Fear can skew our perception of approaching objects, causing us to underestimate the distance of a threatening one, finds a study published in Current Biology.
“Our results show that emotion and perception are not fully dissociable in the mind,” says Emory psychologist Stella Lourenco, co-author of the study. “Fear can alter even basic aspects of how we perceive the world around us. This has clear implications for understanding clinical phobias.”
Lourenco conducted the research with Matthew Longo, a psychologist at Birkbeck, University of London.
People generally have a well-developed sense for when objects heading towards them will make contact, including a split-second cushion for dodging or blocking the object, if necessary. The researchers set up an experiment to test the effect of fear on the accuracy of that skill.
The Power of Music: Mind Control by Rhythmic Sound
You walk into a bar and music is thumping. All heads are bobbing and feet tapping in synchrony. Somehow the rhythmic sound grabs control of the brains of everyone in the room forcing them to operate simultaneously and perform the same behaviors in synchrony. How is this possible? Is this unconscious mind control by rhythmic sound only driving our bodily motions, or could it be affecting deeper mental processes?
The mystery runs deeper than previously thought, according to psychologist Annett Schirmer reporting new findings today at the Society for Neuroscience meeting in New Orleans. Rhythmic sound “not only coordinates the behavior of people in a group, it also coordinates their thinking—the mental processes of individuals in the group become synchronized.”
This finding extends the well-known power of music to tap into brain circuits controlling emotion and movement, to actually control the brain circuitry of sensory perception. This discovery helps explain how drums unite tribes in ceremony, why armies march to bugle and drum into battle, why worship and ceremonies are infused by song, why speech is rhythmic, punctuated by rhythms of emphasis on particular syllables and words, and perhaps why we dance.
The Neuroscience Of Music
Why does music make us feel? On the one hand, music is a purely abstract art form, devoid of language or explicit ideas. The stories it tells are all subtlety and subtext. And yet, even though music says little, it still manages to touch us deep, to tickle some universal nerves. When listening to our favorite songs, our body betrays all the symptoms of emotional arousal. The pupils in our eyes dilate, our pulse and blood pressure rise, the electrical conductance of our skin is lowered, and the cerebellum, a brain region associated with bodily movement, becomes strangely active. Blood is even re-directed to the muscles in our legs. (Some speculate that this is why we begin tapping our feet.) In other words, sound stirs us at our biological roots. As Schopenhauer wrote, “It is we ourselves who are tortured by the strings.”
We can now begin to understand where these feelings come from, why a mass of vibrating air hurtling through space can trigger such intense states of excitement. A paper in Nature Neuroscience by a team of Montreal researchers marks an important step in revealing the precise underpinnings of “the potent pleasurable stimulus” that is music. Although the study involves plenty of fancy technology, including fMRI and ligand-based positron emission tomography (PET) scanning, the experiment itself was rather straightforward. After screening 217 individuals who responded to advertisements requesting people that experience “chills to instrumental music,” the scientists narrowed down the subject pool to ten. (These were the lucky few who most reliably got chills.) The scientists then asked the subjects to bring in their playlist of favorite songs – virtually every genre was represented, from techno to tango – and played them the music while their brain activity was monitored.
Humans demonstrate an inherent bias towards making maladaptive decisions, as shown by a phenomenon known as the gambler’s fallacy (GF). The GF has been traditionally considered as a heuristic bias supported by the fast and automatic intuition system, which can be overcome by the reasoning system. The present study examined an intriguing hypothesis, based on emerging evidence from neuroscience research, that the GF might be attributed to a weak affective but strong cognitive decision making mechanism. With data from a large sample of college students, we found that individuals’ use of the GF strategy was positively correlated with their general intelligence and executive function, such as working memory and conflict resolution, but negatively correlated with their affective decision making capacities, as measured by the Iowa Gambling Task. Our result provides a novel insight into the mechanisms underlying the GF, which highlights the significant role of affective mechanisms in adaptive decision-making.
New research reveals more about how the brain processes facial expressions and emotions
Facial mimicry—a social behavior in which the observer automatically activates the same facial muscles as the person she is imitating—plays a role in learning, understanding, and rapport. Mimicry can activate muscles that control both smiles and frowns, and evoke their corresponding emotions, positive and negative. The studies reveal new roles of facial mimicry and some of its underlying brain circuitry.
New findings show that:
- Special brains cells dubbed “eye cells” activate in the amygdala of a monkey looking into the eyes of another monkey, even as the monkey mimics the expressions of its counterpart (Katalin Gothard, MD, PhD, abstract 402.02).
- Social status and self-perceptions of power affect facial mimicry, such that powerful individuals suppress their smile mimicry towards other high-status people, while powerless individuals mimic everyone’s smile (Evan Carr, BS, abstract 402.11).
- Brain imaging studies in monkeys have revealed the specific roles of different regions of the brain in understanding facial identity and emotional expression, including one brain region previously identified for its role in vocal processing (Shih-pi Ku, PhD, abstract 263.22).
- Subconscious facial mimicry plays a strong role in interpreting the meaning of ambiguous smiles (Sebastian Korb, PhD, abstract 402.23).
Another recent finding discussed shows that:
- Early difficulties in interactions between parents and infants with cleft lip appear to have a neurological basis, as change in a baby’s facial structure can disrupt the way adult brains react to a child (Christine Parsons, PhD).
(Image Credit: iStockphoto/Joan Vicent Cantó Roig)