Tag Archives: #perception

Neuroimaging Reveals How Ideology Affects Race Perception (Neuroscience)

How might people’s political ideology affect their perception of race?

Previous research by Amy Krosch, assistant professor of psychology in the College of Arts and Sciences, has shown that white people who identify themselves as political conservatives tend to have a lower threshold for seeing mixed-race Black and white faces as Black.

More often than liberals, Krosch found, white political conservatives show a form of social discrimination termed “hypodescent” – categorizing multiracial individuals as members of the “socially subordinate” racial group.

In new research published Feb. 22 in Philosophical Transactions of Royal Society B, Krosch used neuroimaging to show that this effect seems to be driven by white conservatives’ greater sensitivity to the ambiguity of mixed-race faces rather than a sensitivity to the Blackness of faces; this sensitivity showed up in a neural region often associated with affective reactions.

Taken together, these study results suggest white political conservatives might overcategorize mixed-race faces as Black not because of an aversion to Blackness, but because of an affective reaction to racial mixing more generally, Krosch said. The study appears in a special issue about political neuroscience.

“We knew from our previous work that conservatives tend to categorize more mixed-race faces as their ‘socially-subordinate’ race, or according to hypodescent,” Krosch said, “a principle closely related to notorious ‘one-drop’ rules, used to subjugate individuals with any nonwhite heritage by denying them full rights and liberties under the law from the earliest days of American slavery through the Civil Rights Era.”

In the new study, Krosch said, she and the other researchers wanted to figure out why this is the case: “Specifically, we wanted to know if conservatives and liberals differ in the way they are literally seeing, thinking or feeling about mixed-race faces.”

Mixed-race faces vary on at least two critical dimensions, Krosch wrote: “Do conservative and liberals differ in their sensitivity to the racial content or racial ambiguity of such faces? Such questions are difficult to separate in behavioral investigations but might be critical to understanding the link between ideology and hypodescent.”

In the new study, the researchers used functional neuroimaging (fMRI) – a proxy for blood flow in regions of the brain – to examine the role of neural mediators of political ideology on discriminatory hypodescent regarding mixed-race faces.

Forty-one self-identified white participants self-reported political ideology on an 11-point scale before the neuroimaging. Members of this ideologically diverse group of individuals were presented with computer-generated face images that ranged from 100% white to 100% Black at 10% increments while neuroimaging captured brain activity.

“Of primary interest was a specific neural region – the insula – because of its relevance in independent investigations of ideology, race and ambiguity,” Krosch wrote. The insula plays a key role in emotional processing, and the anterior insula is associated with processing ambiguity, so it might also be associated with political ideology and hypodescent, she wrote.

In the results, conservatives exhibited a lower threshold for seeing mixed-race faces as Black and this was related to their higher sensitivity to racial ambiguity in the anterior insula. Conservatives also made decisions faster than liberals. Together, these results indicate that conservatives might feel an aversion to racial ambiguity of any kind which causes them to resolve racial ambiguity “quickly and in the most culturally accessible or hierarchy-affirming way – that is, according to hypodescent,” Krosch writes.

Notably, conservatives and liberals did not differ in their responses to ambiguity or face Blackness in brain regions related to lower-level visual processing or social cognition. “Rather than visually perceiving or thinking about mixed-race faces differently, conservatives might maintain a stricter boundary around whiteness (compared to liberals) because of the way they feel about racial ambiguity,” Krosch wrote.

These results advance understanding of the role of political ideology in race categorization, Krosch wrote.

“They also help to explain how and why multiracial individuals are often categorized as members of their most subordinate racial group – a phenomenon that enhances their vulnerability to discrimination and exacerbates existing racial inequalities,” Krosch wrote. “Given the myriad societal consequences of minority-group categorization and the large number of people who are potentially vulnerable to biased categorization, understanding the processes by which ideology reinforces the racial status quo is critically important.”


Reference: Amy R. Krosch, John T. Jost and Jay J. Van Bavel, “The neural basis of ideological differences in race categorization”, Royal Society Publishing B, 2021. https://royalsocietypublishing.org/doi/10.1098/rstb.2020.0139 https://doi.org/10.1098/rstb.2020.0139


Provided by Cornell University

Link Found Between Time Perception, Risk For Developmental Coordination Disorder (Neuroscience)

Neuroscientists at McMaster University have found a link between children who are at risk for developmental coordination disorder (DCD), a common condition that can cause clumsiness, and difficulties with time perception such as interpreting changes in rhythmic beats.

Accurate time perception is crucial for basic skills such as walking and processing speech and music.

“Many developmental disorders, including dyslexia or reading difficulties, autism and attention deficits have been linked to deficits in auditory time perception,” says Laurel Trainor, senior author of the study and founding director of the McMaster Institute for Music and the Mind.

Previous research has shown the brain networks involved in time perception often overlap with the motor control networks required for such activities as catching a ball or tapping along to musical beats. Until now, researchers had not investigated whether children with DCD tended to have auditory timing deficits, despite being at risk for dyslexia and attention deficits.

The study, published online in the journal Child Development, provides new evidence about that connection in children.

A researcher helping a child participant wearing an EEG cap, a non-invasive approach to measure the brain waves. © Auditory Development Lab, McMaster University

Developmental coordination disorder is a common but little-studied condition that affects approximately five to 15 per cent of all children, who can experience a wide range of difficulties with fine and/or gross motor skills. It can have profound and lifelong effects on everyday tasks such as get dressed, writing, and engaging in sports or play, and often interferes with learning, academic performance and socialization.

For this study, researchers recruited more than 60 children aged 6 and 7 years old, who underwent motor skills tests and were assessed either to be at risk for DCD or to be developing typically.

During the first study, each child was asked in a series of trials to pinpoint which of two sounds was shorter in time or had an off-beat rhythm. From this, researchers measured the threshold or smallest time difference at which each child could just barely make the correct judgement.

“We saw that indeed, children at risk for DCD were much less sensitive to time changes compared to typically developing children,” says Andrew Chang, the lead researcher and graduate student in the Department of Psychology, Neuroscience & Behaviour at McMaster.

In the second experiment, researchers used EEG to measure the brain waves of children as they listened to a sequence of sounds that had been tweaked to include occasional timing deviations. Children at risk for DCD had slower brain activity in response to the unexpected timing deviants.

There are no medications to treat DCD, but physiotherapy and occupational therapy can help children improve muscle strength, balance and coordination.

“We know anecdotally that therapists sometimes incorporate regular rhythms into the physical therapy they give to children with DCD, and they have the impression this helps – for example that children can walk better when they walk to a rhythm.” Chang explains.

“Although our current study did not directly investigate any intervention effects, the results suggest that music with salient and regular beats could be used for physiotherapy to help treat children,” he says.

He points to motor rehabilitation featuring auditory cueing with metronomes or musical beats, which helps adult patients who have Parkinson’s disease or are recovering from a stroke. Further research could help to determine whether similar therapies are useful for children with DCD, he says.

Attention editors: A copy of the study can be found at this link:
https://srcd.onlinelibrary.wiley.com/doi/epdf/10.1111/cdev.13537

Featured image: Researchers assessing the motor skills of children © Pediatric Activity & Coordination for Excellence, China Medical University (Taiwan)


Provided by McMaster University

Clumsy Kids Can be Fit Too (Physiology)

Clumsy kids can be as aerobically fit as their peers with better motor skills, a new Finnish study shows. The results are based on research conducted at the Faculty of Sport and Health Sciences of the University of Jyväskylä and the Institute of Biomedicine of the University of Eastern Finland, and they were published in Translational Sports Medicine.

Aerobic fitness doesn’t go hand in hand with motor skills

According to the general perception, fit kids also have good motor skills, while low aerobic fitness has been thought to be a link between poor motor skills and overweight. This perception is based on studies whose methods do not distinguish between the roles of aerobic fitness and body fat content as risk factors for poor motor skills and overweight.

“Our study clearly demonstrated that aerobic fitness is not linked to motor skills when body composition is properly taken into account,” explains Eero Haapala, Ph.D., from the Faculty of Sport and Health Sciences at the University of Jyväskylä.

“Also, aerobic fitness was not strongly associated with overweight or obesity. Therefore, it seems that the role of poor aerobic fitness as a risk factor for poor motor skills and excess body weight has been strongly exaggerated.”

The development of motor skills can be supported

This study did not look at the role of exercise in the development of motor skills, but earlier studies have shown that a range of exercise, varying in motor challenges and intensity, contributes to the development of motor skills, regardless of aerobic fitness and body fat content. Higher levels of physical activity and less sedentary behaviour can also protect against the development of excess weight.

“The key message of our study is that even a child who is unfit can be motorically adept and the heart of a clumsier kid can be as fit as her or his more skilful peer,” Haapala says. “In addition, high levels of varied physical activity and reduced sedentary behaviour are central to the development of motor skills and the prevention of excess weight gain since childhood.”

The study investigated the associations between aerobic fitness, body fat content, and motor skills in 332 children aged 7 to 11 years. Aerobic fitness was measured by maximum bicycle ergometer test and body composition with bioimpedance and DXA devices. Motor skills were measured by common methods.

Reference:

Haapala EA, Gao Y, Lintu N, Väistö J, Vanhala A, Tompuri T, Lakka TA, Finni T. Associations between cardiorespiratory fitness, motor competence, and adiposity in children. Translational Sports Medicine 2020. https://onlinelibrary.wiley.com/doi/10.1002/tsm2.198

Provided by University of Jyväskylä

How Anorexia Nervosa Alters Body Awareness? (Psychology)

Patients with eating disorders automatically slide sideways through doors that are actually wide enough for them. This is an indication of how they unconsciously overestimate their corpulence.

People with anorexia nervosa have a distorted relationship with the dimensions of their body. A study by the team at the Clinic for Psychosomatic Medicine and Psychotherapy at LWL University Hospital at Ruhr-Universität Bochum (RUB) has shown that, in addition to the conscious body image, what is known as the body schema – unconscious body awareness – is also distorted. It normally adapts to the current situation. In patients with anorexia, it could remain at the same level as before the start of the illness. The researchers led by Professor Martin Diers recommend a combination of cognitive behavioural therapy and the use of virtual reality to correct the distorted body schema. The study is published in the International Journal of Eating Disorders on 20 December 2020.

Anorexia patients continue to starve themselves even when they are objectively underweight.  © RUB, Marquard

Understanding the unconscious

The distorted perception of one’s own body is a characteristic symptom of anorexia nervosa. It has long been known that patients overestimate the dimensions of their body. “This discrepancy relates to the conscious part of body perception, body image,” explains Martin Diers. Alongside this is the body schema, unconscious body awareness, which tells us, for instance, where we are in a room. It is usually flexible and adapts to current dimensions. This is why we do not normally bump into things when we are wearing a hat or a rucksack.

In order to find out about this unconscious aspect of body perception, the team from the University hospital developed an experiment involving 23 people with anorexia nervosa and 23 healthy volunteers. To not influence the results, a cover story was used to justify the research which had nothing to do with the real purpose of the study. The experiment consisted of asking the subjects to pass through door frames of different widths. “The opening was adapted to the shoulder width of the subjects and varied between 0.9 times and 1.45 times this width,” says Diers. The researchers then observed from which door width the participants turned sideways before they passed the door.

Even if the door frame was wide enough, anorexics turned in sideways to walk through. © RUB, Marquard

It was shown that patients turn their shoulders to the side with much wider doors than healthy control subjects. “This shows us that they also unconsciously assess their proportions to be larger than they actually are,” concludes lead author Nina Beckmann. The tendency to turn at wider door widths was also accompanied by a negative assessment of one’s own body, which the researchers investigated in various questionnaires. In order to have a positive influence on the distorted unconscious body perception and adapt the person’s possibly outdated body schema to suit their current physical proportions, the research team recommends using virtual reality alongside cognitive behavioural therapy. This makes it possible to virtually step into another person’s body for a certain amount of time and influence the representation of the body.

Reference: Nina Beckmann, Patricia Baumann, Stephan Herpertz, Jörg Trojan, Martin Diers: How the unconscious mind controls body movements: body schema distortion in Anorexia nervosa, in: International Journal of Eating Disorder, 2020, DOI: 10.1002/eat.23451 https://onlinelibrary.wiley.com/doi/10.1002/eat.23451

Provided by Ruhr Universität Bochum

Per­ceiv­ing Pros­thesis as Lighter Thanks to Neur­o­feed­back (Biology)

Trans­mit­ting sens­ory sig­nals from pros­theses to the nervous sys­tem helps leg am­putees to per­ceive pros­thesis as part of their body. While am­putees gen­er­ally per­ceive their pros­theses as heavy, this feed­back helps them to per­ceive the pros­theses as sig­ni­fic­antly lighter, ETH re­search­ers have shown.

Signals from tact­ile sensors un­der the sole of the pros­thetic foot and from angle sensors in the elec­tronic pros­thetic knee joint are passed on to the nervous sys­tem. (Visu­al­isa­tions: ETH Zurich)

Leg am­putees are of­ten not sat­is­fied with their pros­thesis, even though the soph­ist­ic­ated pros­theses are be­com­ing avail­able. One im­port­ant reason for this is that they per­ceive the weight of the pros­thesis as too high, des­pite the fact that pros­thetic legs are usu­ally less than half the weight of a nat­ural limb. Re­search­ers led by Stan­isa Raspop­ovic, a pro­fessor at the De­part­ment of Health Sci­ences and Tech­no­logy, have now been able to show that con­nect­ing the pros­theses to the nervous sys­tem helps am­putees to per­ceive the pros­thesis weight as lower, which is be­ne­fi­cial for their ac­cept­ance.

To­gether with an in­ter­na­tional con­sor­tium, Raspop­ovic has de­veloped in re­cent years pros­theses that provide feed­back to the wearer’s nervous sys­tem. This is done via elec­trodes im­planted in the thigh, which are con­nec­ted to the leg nerves present there. In­form­a­tion from tact­ile sensors un­der the sole of the pros­thetic foot and from angle sensors in the elec­tronic pros­thetic knee joint are con­ver­ted into pulses of cur­rent and passed in to the nerves.

“To trick an above-​knee am­putee’s brain into the be­lief that the pros­thetic leg was sim­ilar to his own leg, we ar­ti­fi­cially re­stored the lost sens­ory feed­back,” says ETH pro­fessor Raspop­ovic. In a study pub­lished last year, he and his team showed that wear­ers of such neur­o­feed­back pros­theses can move more safely and with less ef­fort.

Be­ne­fi­cial in­volve­ment

In a fur­ther study, the sci­ent­ists were now able to show that neur­o­feed­back also re­duces the per­ceived weight of the pros­thesis. They pub­lished the res­ults in the journal Cur­rent Bio­logy.

In or­der to de­term­ine how heavy a trans­femoral am­putee per­ceives their pros­thetic leg to be, they had a vol­un­tary study par­ti­cipant com­plete gait ex­er­cises with either neur­o­feed­back switched on or off. They weighed down the healthy foot with ad­di­tional weights and asked the study par­ti­cipant to rate how heavy he felt the two legs were in re­la­tion to each other. Neur­o­feed­back was found to re­duce the per­ceived weight of the pros­thesis by 23 per­cent, or al­most 500 grams.

The sci­ent­ists also con­firmed a be­ne­fi­cial in­volve­ment of the brain by a motor-​cognitive task, dur­ing which the vo­lun­teer had to spell back­wards five-​letter words while walk­ing. The sens­ory feed­back not only al­lowed him to have a faster gait but also to have a higher spelling ac­cur­acy.

“Neur­o­feed­back not only en­ables faster and safer walk­ing and pos­it­ively in­flu­ences weight per­cep­tion,” says Raspop­ovic. “Our res­ults also sug­gest that, quite fun­da­ment­ally, it can take the ex­per­i­ence of pa­tients with an ar­ti­fi­cial device closer to that with a nat­ural limb.”

Ref­er­ence: Preatoni G, Valle G, Pet­rini FM, Raspop­ovic S: Light­en­ing the per­ceived pros­thesis weight with neural em­bod­i­ment pro­moted by sens­ory feed­back. Cur­rent Bio­logy, 7 Janu­ary 2021, doi: 10.1016/j.cub.2020.11.069

Provided by ETH Zurich

How Can Fathers Shape Their Daughters’ Body Image? (Psychology)

Study analyzes fathers’ communication with young daughters about their body image.

The holidays are coming up, and when tables become overflowed with plates and bowls of delicious foods, be thoughtful with the way you talk about the food with your children. It can be common for children to feel pressure and insecurities about their bodies, and it turns out, parents can play a large role in children’s perception of their bodies.

Though she is the Director of the Center for Body Image Research at the University of Missouri, even Virginia Ramseyer Winter still often worries if her family is doing everything they can to make sure her daughter has a positive relationship with her body.

“I have a daughter that falls in this age range, between 5 and 10, so certainly it’s something that I’m always navigating at home, and my spouse— her dad— is also navigating,” Ramseyer Winter said. “You know, I work in this field and its still really tricky. How do you talk about food in a way that helps kids develop a healthy relationship with it and prevent eating disorders, and focus on their character as opposed to the way they look?”

While much of the previous research around the role parents take in their children’s body image focuses on the mother, there is little research about fathers’ role. So, in a recent study, Ramseyer Winter, in collaboration with Jaclyn Siegel at Western University and Mackenzie Cook at the University of Missouri, analyzed fathers’ strengths and barriers when it comes to communicating with their young daughters about their body image.

The researchers found through interviews that fathers tend to understand the importance of a healthy self-body image among their children. However, they often felt uncomfortable discussing body image and health with their daughters.

“Unsurprisingly, all of the dads we talked to really are interested in addressing this with their daughters. They know it’s important and they place a lot of value on it,” Ramseyer Winter said. “However, we found that there are some common barriers. They are struggling to have these conversations, and many of them are conflating health with body size.”

The 30 fathers interviewed identified several common barriers when attempting to discuss bodily health with their daughters, including a lack of confidence in uncomfortable conversations, gender differences with their daughters, and a recognition of their daughter’s discomfort with discussing their bodies. The study also found that the fathers noticed that their daughters can take negative statements about their own bodies and positive statements about other people’s body to heart.

There has been little prior research stating that fathers can have a positive impact on their daughter’s self-body image. In this study, researchers found the fathers attempted to have positive impacts by praising their daughters’ skills, strengths and talents instead of their body and accepting the way their daughters choose to present themselves. Ramseyer Winter said that understanding these conversations can help fathers learn what resources may be necessary to prevent some of the issues that can cause negative perceptions of body image at a young age.

“Dads obviously influence their children, so we need to understand what fathers are doing, and what is and isn’t working. There wasn’t much discussion on that topic before this study,” Ramseyer Winter said. “My hope is that this research can help to ultimately develop interventions that are easily accessible for fathers and their children to positively impact body image development. If we can prevent negative body image perceptions early on in children’s life, we can impact health and mental health outcomes long-term.”

Ramseyer Winter also said that if parents are looking for advice on how to help their children grow with a healthy perception of their body, there are currently a few resources they can utilize, including books on intuitive eating and Health at Every Size.

References: Jaclyn A. Siegel, Virginia Ramseyer Winter, Mackenzie Cook, “It really presents a struggle for females, especially my little girl”: Exploring father’s experiences discussing body image with their young daughters”, Body Image, Volume 36, 2021, Pages 84-94, ISSN 1740-1445, https://doi.org/10.1016/j.bodyim.2020.11.001.
http://www.sciencedirect.com/science/article/pii/S1740144520304228

Provided by University of Missouri

How One Pain Suppresses The Other? (Neuroscience)

The body knows various mechanisms that dampen painful sensations. They can be examined with new methods.

When two painful stimuli act on us at the same time, we perceive the one of them as less painful. This phenomenon is part of the body’s own pain control system. A disfunction of this inhibition is associated with chronic pain disorders. Researchers at Berufsgenossenschaftliches Universitätsklinikum Bergmannsheil, clinic of Ruhr-Universität Bochum (RUB), have developed a method for this. They were able to show that the method works effectively with both painful electrical stimuli and heat pain. Two consecutive studies on this have been published in the journals Brain Sciences and BMC Neuroscience.

The body knows several mechanisms that influence the perception of pain. © RUB, Marquard

The same stimulus hurts differently

The human perception of pain can vary greatly depending on the situation. So it is possible that the same pain stimulus feels more or less painful under different conditions. The body’s own pain control system is responsible for this. Researchers investigate this system with the research method called Conditioned Pain Modulation, or CPM for short. “This records how strongly a painful stimulus inhibits the experience of another painful stimulus that is presented at the same time,” explains Assistant Professor Dr. Oliver Höffken, neurologist at Bergmannsheil.

In the first study, the research team compared an established CPM model with a recently introduced variation. With Conditioned Pain Modulation, two pain stimuli always play a role. The first stimulus, also called the test stimulus, is administered twice: once alone and once in conjunction with the second stimulus, the conditioning stimulus. The test person should assess how painful the test stimulus was on its own and how it felt while the conditioning stimulus was administered.

An objective criterion

In the current work, the team led by Oliver Höffken, Dr. Özüm Özgül and Professor Elena Enax-Krumova compared two different test stimuli: a tried and tested stimulus caused by heat pain and a new one triggered by electrical stimulation of the skin. In both cases the conditioning stimulus was generated by cold water. The electrical stimulation of the skin has a decisive advantage over the previously used heat method: it allows the changes in brain activity triggered by the electrical stimuli of the skin to be measured with the help of EEG recording. This adds an objectively measurable criterion to the subjective pain assessment of the test persons.

Two mechanisms with the same result

In the second study, the researchers used the previously tested CPM model with the electrical stimulation of the skin and compared it to the pain-relieving effect of cognitive distraction. They found that both the CPM method and cognitive distraction can reduce the sensation of pain to a similar degree. However, the two methods showed different results in the measurement of the electrical potentials. “Based on our measurements, we assume that the two pain-relieving effects examined are two different neural mechanisms that just lead to the same effect,” says Höffken.

The researchers carried out their studies on healthy volunteers. However, research into the body’s own pain inhibition system is also relevant in order to better understand various pain disorders. “In patients with chronic pain, the development of postoperative pain and the transition from acute to chronic pain, changed CPM effects have already been found in the past. In our research group, we therefore use the CPM model as an instrument to investigate mechanisms in the processing of painful information”, explains Höffken.

The study was partly financed through grants of the Collaborative Research Centre (CRC) 874 at RUB, which is supported by the German Research Foundation since 2010. The CRC “Integration and representation of sensory processes” investigates how sensory signals generate neuronal maps, and result in complex behaviour and memory formation.

References: (1) Elena Enax-Krumova, Ann-Christin Plaga, Kimberly Schmidt, Özüm S. Özgül, Lynn B. Eitner, Martin Tegenthoff and Oliver Höffken: Painful cutaneous electrical stimulation vs. heat pain as test stimuli in conditioned pain modulation, in: Brain Sciences, 2020, DOI: 10.3390/brainsci10100684 (2) A. T. Lisa Do, Elena Enax-Krumova, Özüm Özgül, Lynn B. Eitner, Stefanie Heba, Martin Tegenthoff, Christoph Maier, Oliver Höffken: Distraction by a cognitive task has a higher impact on electrophysiological measures compared with conditioned pain modulation, in: BMC Neuroscience, 2020, DOI: 10.21203/rs.3.rs-26882/v3

Provided by RUB

Middle-ear Implants Improve Hearing Over the Long Term (Medicine)

Study by Karl Landsteiner University of Health Sciences in Krems finds lasting improvement in word recognition among patients with middle-ear implants in the part of the ear known as the round window.

Audibly good: Special middle ear implants also improve hearing in the long term © Karl Landsteiner University

Middle-ear implants that stimulate auditory nerves via the round window can improve hearing for many years. In most cases, these electronic hearing aids can be implanted and used without any problems. Complications are limited to patients who have previously had benign tumors removed from their middle ear. These are the recently published findings of a study of 46 individuals carried out at Karl Landsteiner University of Health Sciences in Krems (KL Krems). The study considered periods of as much as six years after implantation, making it one of the first long-term investigations of the effectiveness of these specialized middle-ear implants.

Middle-ear implants are often a simple but effective means of improving people’s hearing. Alongside other technologies, a device called a Vibrant Soundbridge (VSB) has proved its worth. This technology converts sound waves into mechanical vibrations which are then passed on to the auditory structures in the middle ear. This process can stimulate different parts of the middle ear. A method adopted in the past few years is based on connecting the VSB with the round window, which joins the inner and middle ear. Several studies have demonstrated the short-term benefits of the operation forpatients, but until now, little data has been collected on the question ofwhether the method is also successful in the long run. A study by KL Kremshas now filled this gap.

Improvement lasts several years

The study looked at 46 patients who had a VSB that was implanted an averageof just over 2.5 years previously—although in one case the individual had had the device for over six years. “Even after such lengths of time we were still able to measure a clear—and statistically highly significant—improvement in word recognition among the subjects,” says Univ.-Prof. Georg Mathias Sprinzl, head of the Ear, Nose and Throat Department at St. Pölten University Hospital—which is part of KL Krems—outlining the positive long-term effectof VSB implants in the middle ear. The study also found that the surgical procedure and implantation of a miniature device did not have an adverse impact on the patients’ residual hearing.

The implant is suitable for people who have problems with sound-wave transmission or suffer mixed hearing loss, but fitting it is a highly complex operation that requires not only high-end devices but also a surgeon with extensive experience and outstanding surgical skills. Prof. Sprinzl is an internationally recognized expert in this field, with more than 320 surgical VSBimplants—more than half of them in the past six years alone—to his name. “This operation demands such a high degree of experience because the VSB can be connected with various structures in the middle ear,” he explains, referring to the challenge associated with this specialized treatment option. “At the same time, it opens up a huge range of possibilities so we can implant the device in a way that achieves the best possible result for each individual patient.” As shown by the results of the study, which has been published in The Laryngoscope, the procedure is particularly complex if a tumor (known as a cholesteatoma) has to be removed from the patient’s middle ear beforehand. All seven of the subjects who required multiple operations had suffered fromthe condition.

The middle-ear implant works by transforming sound waves into vibrations. An audio processor fitted behind the ear picks up sounds in the form of sound waves and transmits them through the skin to the VSB implant in the middle ear. The VSB turns the waves into vibrations, replicating the natural hearing process. Then the mechanical vibrations stimulate the cochlea, which sends audio signals to the brain via auditory nerves, creating auditory perception.

According to the study, the average length of time for which these leading-edge technical products are worn—a substantial 13 hours a day, encompassing virtually the entire daytime—is an indicator of the benefits for patients who undergo the painstaking implantation. Like other such investigations, this study has again enabled KL Krems to highlight the importance for medical engineering of close collaboration between clinical and academic activities, which generates real improvements in patients’ quality of life.

References: Georg Mathias Sprinzl et al. Long‐Term Stability and Safety of the Soundbridge Coupled to the Round Window, The Laryngoscope (2020). DOI: 10.1002/lary.29269 https://doi.org/10.1002/lary.29269

Provided by Karl Landsteiner University

Hallucinations Induced in Lab Could be Key to Better Understanding And Treatment (Neuroscience)

Cognitive neuroscientists from UNSW Sydney say if we really want to understand and treat the pathological hallucinations that affect people with physical and mental illnesses, the best place to start is in the laboratory.

Hallucinations have been difficult to study and can be distressing for the person experiencing them, but hallucinations induced in the lab are much more benign. Credit: Shutterstock

Inducing hallucinations in the general population using visual stimulation procedures works similarly to illusions, and enables more objective and repeatable testing. It’s also much less distressing to the test subject than studying pathological hallucinations experienced by people with conditions like Parkinson’s disease or schizophrenia.

“By nature, [lab-induced hallucinations] can be induced in almost anyone at any time,” the neuroscientists write in an opinion piece published recently in Philosophical Transactions B journal.

“This can help to curb the current overreliance on studying pathological hallucinations, thereby reducing burdens placed on patients and simplifying recruitment and testing logistics.”

Seeing something that isn’t there

Most people naturally think of visual hallucinations as being realistic images or scenes, such as seeing humans or spiders (what we call ‘complex’ hallucinations). However, a hallucination in its broadest sense can be defined as the experience of seeing something that is not there. As such, visual hallucinations can also include seeing basic geometric shapes or colors (referred to as ‘simple’ hallucinations), and scientists can trigger both simple and complex hallucinations in the laboratory.

Professor Joel Pearson, the senior author of the opinion piece, says work the group did in 2016 showed that you could induce hallucinations in people reliably and safely using specific types of flickering lights.

“We showed that you could use flickering lights in an annulus—basically a flickering white ring like a doughnut on a black background—and you could induce hallucinations of little dark blobs which rotate around the ring,” he says.

“And you could use that to try and study the mechanisms behind visual hallucinations. But those flicker hallucinations are just the tip of the iceberg, and there are many other techniques for inducing hallucinations that are similar to pathological hallucinations in terms of the experience and underlying neural processes.”

Prof. Pearson says one of the trickier problems is working out which techniques can tell us something about pathological hallucinations.

“A lot of this work shows that it’s hard to separate hallucinations from illusions and veridical (reality-based) perception. Current hallucination definitions are too black and white, and aren’t up to the task of classifying many of these lab-induced experiences.”

Spectrum of experience

Professor Pearson and fellow authors Dr. Sebastian Rogers and Dr. Rebecca Keogh use a continuous spectrum of experience to distinguish hallucinations from other types of perception, based on the similarity between the physical stimulation of the senses (the light that enters the eye) and the actual conscious experience (the image we ‘see’ or experience).

Veridical perception (involving a strong relationship between what is ‘in reality’ and what one sees) is at one end of this spectrum and hallucinations (a weak relationship between what is present in reality and with what one sees) is at the other, with illusions falling somewhere in between.

According to lead author Dr. Rogers, “the thesis of the idea is that the further a lab-induced experience is toward the hallucination end of the spectrum, the more it can tell us about other types of hallucination.”

“If you really don’t want to call one of these lab-induced experiences a hallucination, that’s fine by us. We don’t really mind what the name is, we care most about whether we can study it to learn about pathological and other hallucinations. It’s a way to investigate hallucinatory processes any time we want in the lab, with anyone.”

Dr. Keogh says, “once we understand the underlying mechanisms, that is, what in the brain leads to seeing things that aren’t there, then we’ll be able to develop treatments. There are very few treatments for hallucinations at the moment, and most are medications that can lead to unwanted side effects.

“Using lab hallucination models can allow us to develop new avenues for more targeted treatments, such as electrical or magnetic brain stimulation.”

References: Sebastian Rogers et al. Hallucinations on demand: the utility of experimentally induced phenomena in hallucination research, Philosophical Transactions of the Royal Society B: Biological Sciences (2020). DOI: 10.1098/rstb.2020.0233

Provided by University of New South Wales