Fundamental Frequency of Sound as Unique Animal Communication

 

Human auditory perception is so complex that we have the ability to distinguish people based on the slightest differences in their voice. The differences go beyond just pitch or volume, and many people use the word "color" to describe the specific tonal specialty of an individual, whether they are singing or simply talking. This "color" is what makes us instantly turn when hearing someone we know instead of lumping all background voices together. This "color" has a technical term; fundamental frequency, or F0, and this determines the uniqueness of human voice, and also, animals 'voices' too.

The paper "Auditory biological marker of concussion in children" by Nina Kraus et. al. relates fundamental frequency and other aspects of auditory processing to how brain damages experienced after a concussion. By comparing graphs of auditory perception from an individual pre and post traumatic brain injury, it can be determined whether damage has been done from said injury and whether it is to the extent of a concussion. Since concussions have no acute diagnostic test, being able to observe damage in this way could be a very beneficial diagnostic tool. Fundamental frequency, then, is a highly complex and special feature of auditory production and processing.

Furthermore, Kraus et. al. states that "tracking the F0 facilitates pitch perception, identifying sounds and talkers, and understanding stress and prosody," (Kraus, 2016) so not only is our processing of F0 useful for identifying the owner of a sound, but also what to interpret from the sound, on a very subtle level. This could mean that outside of intentional tone used by an individual when speaking, the very F0 of their voice could dictate some level of tonal perception as well. Maybe some fundamental frequencies innately have an off-putting expression, and some are more calming and inviting. This could be an explanation for certain "vibes" people may put off when they speak, an intangible perception others receive audibly that affects how they perceive the person as a result.

Humans are not the only creatures who have a fundamental frequency of sound, but animals do as well. They communicate in their own ways and can probably distinguish members of their species similarly to how humans do. However, there is one animal who has an extra layer of uniqueness to their fundamental frequency and sound they produce, and that is the horse. Horses have long been known to have a unique sound when they whinny, but now it is understood how; in one sound, horses produce two fundamental frequencies. There is a low-pitched sound from vibrating the larynx, like when humans sing, and simultaneously there is a high-pitched whistling from the vocal cords, unusual to most large animals. In a statement to Scientific American by co-author of the paper that discusses these findings, Élodie Briefer says “In the past, we found that these two frequencies are important for horses, as they convey different messages about the horses’ own emotions,” (Briefer, 2026). I think it is interesting that horses are one animal that has evolved to have two separate mechanics of sound production. There are birds for example that can produce two separate whistle sounds simultaneously, but they come from the same system, unlike the whistling and vibration patterns of a horse's whinny.

Both the paper by Kraus et. al. and the study about horses illustrate a unique auditory concept, fundamental frequency, and show how it has great value among humans as well as other animals. of sound. The findings about horses and how their F0 is a factor in their emotional communication could provide insight into how F0 conveys emotion and tone, and this could translate into human communication as well. Fundamental frequency is an evolutionarily conserved mechanism for communication in specifying certain things, like owner and pitch, but there is something extra special about the way horses have evolved with it, allowing them to produce multiple F0s through different mechanisms. I am interested to see where these findings take scientists in the fields of neuroscience, auditory mechanisms, and human and animals processes.

 

References:

Kraus, Nina et. al. 2016. Auditory biological marker of concussion in children. Scientific Report retrieved from Nature.com

Mogensen, Jackie Flynn. “Horses Whinny by Making Sounds in a Unique Way That Is Not Seen in Other Animals.” Scientific American, Scientific American, 25 Feb. 2026, www.scientificamerican.com/article/how-horses-whinny-has-long-been-a-mystery-now-scientists-think-they-know-the/.

Potential Drug Suppresses a Key Hallmark of Alzheimers

    

Potential Drug Suppresses a Key Hallmark of Alzheimers     

The loss of synaptic connections is a key predictor of Alzheimer's disease. This irreversible neurodegenerative brain disorder destroys memory and thinking, eventually destroying the ability to perform simple everyday tasks. Amyloid-β is a peptide that is especially prone to misfolding and aggregation, which abnormally accumulates in AD patients, initiating synaptic dysfunction. Synaptic loss and the accumulation of Aβ strongly correlate with impairment in AD, yet the mechanism linking the origin of this loss and the pattern it follows remains unclear. 

Upon taking Introduction to Neuroscience, I had an assignment in which I explored recent news about Alzheimer's disease. This study targeted arginine-Aβ in mice, how it accumulates early, drives inflammation, and precedes behavioral impairment. This past semester, I was able to listen to Dr. Delgado explain his research. In the study “Pin1 binding to phosphorylated PSD-95 regulates the number of functional excitatory synapses," Dr. Delgado and colleagues suggest a molecular mechanism by which the phosphorylation of PSD- 95, a postsynaptic density protein, recruits Pin-1 and decreases the number of functional synapses. When reading his research article, I began to understand the connection that can be made to findings I had previously read about.  

The study, "Oral administration of arginine suppresses Aβ pathology in animal models of Alzheimer’s disease," follows the study of a potential drug that can reverse aggregates present in Alzheimer's cases. The team evaluated Aβ, a key hallmark of Alzheimer's, in different animals carrying different mutations. Scientists tested the peptide to see if the drug, arginine, stops the accumulation of Aβ.  Findings from Kindai University suggest that reduced Aβ aggregation leads to less kinase overactivation. The less pathological phosphorylation leads to less Pin1 recruitment, and the preserved PSD- 95 maintains excitatory synapses. Aβ aggregation likely leads to the phosphorylation events that enable Pin1- mediated synaptic loss. The results were promising as both accumulation and toxicity were mitigated, as well as behavioral performance improvement and a reduction of neuroinflammation.

These findings lend support to a theory where incorrect phosphorylation signaling triggered by Aβ aggregation destabilizes postsynaptic scaffolding through Pin1and PSD-95 interactions, resulting in synapse loss. This synaptic loss may be reversed through interventions such as the drug arginine, which has shown to suppress aggregation and indirectly protect synapses by preventing activation of this destabilizing pathway. These findings open new possibilities for developing new strategies and treatments for neurodegenerative diseases. 

Together, these studies highlight how Alzheimer’s disease progression may be driven not only by the presence of amyloid-β, but by the molecular signaling cascades it initiates at the synapse. By linking Aβ aggregation to abnormal phosphorylation events that destabilize postsynaptic scaffolding through Pin1 and PSD-95, this work helps clarify how early synaptic loss emerges and spreads before widespread disease progression. Importantly, the ability of arginine to suppress Aβ aggregation and reduce downstream pathological signaling suggests that targeting early aggregation events may preserve synaptic integrity and slow cognitive decline. Because aggregations and protein misfolding are central to a great variety of neurodegenerative diseases, these findings can have broader applications beyond just Alzheimer’s. Together, these findings emphasize the value of combining molecular, synaptic, and behavioral approaches to better understand Alzheimer’s disease and to guide the development of disease-modifying therapies aimed at protecting synaptic connections, such as arginine.  Alzheimer’s breakthroughs bring us closer to slowing and reversing memory loss. It is compelling as these advances offer hope for protecting and preserving the moments that matter most.

References 

Delgado, J. Y.; et al. Pin1 Binding to Phosphorylated PSD-95 Regulates the Number of Functional Excitatory Synapses. Neurochemistry International 2025, 186, 105835. https://doi.org/10.1016/j.neuint.2025.105835

Fujii K, Takeuchi T, Fujino Y, Tanaka N, Fujino N, Takeda A, Minakawa EN, Nagai Y. Oral administration of arginine suppresses Aβ pathology in animal models of Alzheimer's disease. Neurochem Int. 2025 Dec;191:106082. doi: 10.1016/j.neuint.2025.106082. Epub 2025 Oct 30. PMID: 41175945.

The Influence of Gesture on Conformity

 Recently, I was given the opportunity to listen to Dr. Elizabeth Wakefield discuss her research findings on the relationship between speech and gesture in language comprehension. From her research, Wakefield and her colleagues determined that the amount of attention given to gestures while someone is speaking is influenced by a person’s proficiency in the language. To determine this, Wakefield and her colleagues tracked the eye movements of bilingual children with a stronger proficiency in one language than the other as they watched several lectures in both languages. This allowed the researchers to analyze how often the children attended to the hand gestures and compare it with their comprehension of the lecture. The data showed that a lower language proficiency lead to a higher attentiveness to the gestures of the lecturers.

After hearing Dr. Wakefield talk about her and her colleagues findings from this study,  I was reminded of the Asch Conformity Experiment on peer pressure and assimilation I had learned about previously. The Asch Conformity Experiment examined what it takes for a person to ignore what they know to be true because of the opinions of others. In this study, one participant was asked an easy question after witnessing several confederates intentionally answer the same question incorrectly. Similar to the later Stanford Prison Experiment, researchers concluded that it takes little pressure for people to deny what they believe to be true and conform to a group.

Based on these two studies, I believe that further research should be conducted on the relationship between gestures and body language and how they influence our likelihood of forsaking our beliefs to conform to perceived expectations. Exploring this connection could further our understanding of how gestures can be effectively used in the classroom to support student learning as well as identify the factors that lead people to go against their personal knowledge or even compromise their moral code under social pressure.

Asch, S. E. (1952). Effects of group pressure upon the modification and distortion of judgments. In H. Guetzkow (Ed.), Groups, leadership, and men. Carnegie Press. https://gwern.net/doc/psychology/1952-asch.pdf

Zielinski, N., & Wakefield, E. M. (2021). Language proficiency impacts the benefits of co-speech gesture for narrative understanding through a visual attention mechanism. Proceedings of the Annual Meeting of the Cognitive Science Society. https://escholarship.org/uc/item/63r5d3qq

Helmet to Helmet to Concussion

Concussions are becoming more common, especially in professional athletes, but also in children who play contact sports. Although diagnosing a concussion can be very ambiguous, there is hope for a better diagnostic tool for concussions as well as advanced protective gear, such as helmets, that can prevent concussions altogether. 

In a recent seminar presentation at Loyola University Chicago, Jennifer Krizman spoke about her research article “Auditory biological marker of concussion in children”, which investigated alternative testing for concussion diagnosis in children, specifically measuring speech-evoked frequency-following responses (FFRs) and neural processing of the fundamental frequency of speech (F0). During Krizman’s study, she measured the FFRs and F0 responses of children who had been diagnosed with a concussion and she found that they had smaller responses compared to children without a concussion. Children diagnosed with a concussion also had poorer pitch coding and slower responses to half of the auditory neural processing features. Severity of the concussion also made larger differences in the auditory neural processing, suggesting concussion severity plays a significant role in speech processing. Krizman’s research suggests that concussions disrupt the auditory neural processing pathway and measuring FFRs and F0 responses could be a potential tool to better diagnose concussions since there is no one singular test for a concussion. 

An article by Adrian Cho titled “Softening the Blow” described the technology behind sport helmets and how they are always evolving year to year to lessen the risk of athletes getting concussions. The Virginia Tech helmet lab is one of the foremost manufactures of the sport helmet and they are evolving their designs each year to try to decrease the concussion rates across professional and college sports. The NFL concussion rate has been steadily declining with improved helmet design, but it will be difficult to determine if the improved helmet design reduces the incidence of chronic traumatic encephalopathy (CTE), which is a disease similar to Alzheimer’s disease and is caused by the repeated blows to the head. Researchers explain that the risk of concussion depends on the dynamics of the hit, specifically if it is linear or rotational acceleration, which can cause the brain tissue to twist and deform. Helmets are more flexible than before to allow the helmet to absorb the shock of a hit. Researchers in the Virginia Tech helmet lab reproduce hits at six different locations and three different speeds to test the helmets. But some critics argue that this type of stationary testing is not accurate because no one has ever stood still during a game and gotten hit. Concussions most likely occur during physical movement, so the testing protocols need to work in more dynamic impact tests to truly understand the science behind concussions and how to keep athletes safe. 

Both Krizman’s research article and Cho’s news article bring to light the dangers of concussions and explore different opportunities to improve concussion protocol. Krizman dives into the testing aspect for concussion diagnosis whereas Cho explains the evolution of sport helmet safety and concussion prevention. They both are interested in preventing concussions and long-term effects, which is something very important in the sports community, especially in young children, but also high school, college, and professional athletes.

References: 

Kraus, N., Thompson, E. C., Krizman, J., Cook, K., White-Schwoch, T., & LaBella, C. R. (2016). Auditory biological marker of concussion in children. Scientific Reports, 6(1). https://doi.org/10.1038/srep39009 

Cho, A. (2026). Softening the Blow: Inside the quest to make a safer football helmet. AAAS Articles DO Group. https://doi.org/10.1126/science.zs6zhs0

Rhythmic experiences such as playing Tetris can mitigate neurological trauma symptoms

    If you have ever observed a competitive Tetris player in the midst of the game, you may have noticed that there is a certain rhythm which the player adopts. The way the blocks are spun and placed down begin to follow a certain flow, not much different from the beat of a song. In a recent study conducted by the Max Planck Institute for Human Development, it is revealed that patients diagnosed with post-traumatic stress disorder (PTSD) from witnessing extreme violence had a significant reduction of symptoms and increase in hippocampal brain matter when their treatment plan had included playing Tetris once a day over a period of time (1). 

    Participants in the study had very recent exposure to a traumatic event while serving in the German Federal Armed Forces. Prompt treatment following exposure to the traumatic event had been essential to the study, as the study aimed at diminishing the consolidation of the traumatic memory. One group of discharged individuals was instructed to play Tetris for an hour a day and for 25 minutes following an intrusive memory in addition to treatment with eye movement desensitization and reprocessing (EMDR) therapy. A control group had only been treated for PTSD with EMDR therapy. After 6 months of treatment, the Tetris group had a greater remission of PTSD symptoms, particularly anxiety, than did the non-Tetris group according to before and after questionnaire results. Furthermore, MRI neuroimaging revealed that the Tetris group had an increase in hippocampal volume that the non-Tetris group did not demonstrate.

    Recently, I had the honor to sit in on a talk by Dr. Jennifer Krizman at Loyola University Chicago. She was discussing her work on auditory processing changes in children that have sustained concussions while playing a sport (2). Her study showed that children who had recently sustained concussions had issues with processing fundamental frequencies in speech, which is the primary pitch produced by a sound. When exposed to an auditory stimulus, the frequency-following response (FFR) that is produced in the brain is weakened in children with concussions, diminishing their understanding of speech and lowering overall synchrony in brain function. 

    Dr. Krizman began to discuss how having a concussion disrupted the rhythmic capabilities of patients, and that the very brain processes that are hindered by concussion are seen to be enhanced in musicians. People who were better at holding a rhythm also showed advantages in ability to encode sound. Dr. Krizman emphasized the importance of rhythm in our fundamental tasks as humans, explaining that rhythm is essential to life, such as with circadian rhythms and auditory processing. She shared that rhythm training in concussed individuals yielded promising results with alleviating concussion symptoms, so much so that it could be used as a potential concussion treatment.

    I found this information particularly interesting, thinking back to the study about PTSD treatment with Tetris. In both scenarios, rhythmic experiences had the ability to support brain growth in a way that allowed individuals to recover from brain trauma. This poses the question whether there are other rhythmic experiences that may be a viable supplement for brain trauma treatment, PTSD or not. Perhaps rhythm games other than Tetris could be beneficial to brain recovery following trauma, such as Guitar Hero and others. Some individuals may benefit from more physical rhythmic activities such as dance or learning a new instrument. This prospect of rhythm as treatment for trauma opens up many doors for discovery and life-changing care. Without a doubt, it is something worth looking into.

References

(1) Butler, Oisin, et al. “Trauma, treatment and Tetris: Video gaming increases hippocampal volume in male patients with combat-related posttraumatic stress disorder.” Journal of Psychiatry and Neuroscience, vol. 45, no. 4, July 2020, pp. 279–287, https://doi.org/10.1503/jpn.190027.

(2) Kraus, Nina, et al. “Auditory biological marker of concussion in children.” Scientific Reports, vol. 6, no. 1, 22 Dec. 2016, https://doi.org/10.1038/srep39009.

It's Just a Headache, I'm Fine!

     It's no secret that young athletes often lie or understate their concussion symptoms to achieve their maximum playing time. To non-athletes, this may sound irresponsible, but there are several valid reasons as to why a player wouldn't want to disclose the true depth of their pain. Many high school level athletes are looking to be scouted for scholarships, and if this player comes from a low-income family, the playing time they have is their ticket to an education. Athletes currently playing in college have scholarships riding on their time participating in their sport, and many of them are trying to make careers of their game. Being labeled as concussed several times would be bad for their brand and/or hurt their chances of getting drafted. A major reason is that many young people just don't think their injuries are that serious. They don't report pain because they assume it'll go away soon enough, or that a small level of pain is typical after a head injury (Archambault 2023) . 

    Much of concussion diagnoses rely on these self-reported symptoms. Physicians do not currently have an objective method of testing for concussion, which is where Dr. Krizman's research becomes relevant. I was privileged to attend a seminar where Dr. Krizman presented research done to synthesize a reliable approach to concussion diagnosis that is clinically adoptable. The researchers tested the validity of speech-evoked frequency-following responses (FRRs) as a biological indication of traumatic brain injuries in children (Kraus et al., 2016). This test measures neural responses in the auditory midbrain, a region that may reflect damage beyond the auditory system. This method is inexpensive, non-invasive, and objective in diagnosing concussions. The most important findings of this research were that FFRs have potential to be used in the clinical setting, and that the negative cognitive effects detected by the FFRs were still detected after patients reported physical symptoms to improve. This implies that the damage sustained from concussions is persistent even if the patient truly does feel improvement. 

    These findings beg the question, what are the long-term effects of living with an untreated concussion? What can develop after multiple untreated impacts to the head? One of the most talked about conditions relevant to this discussion is CTE, chronic traumatic encephalopathy. This condition is a brain disease that is thought to be caused by repeated head traumas, which often occur in intense contact sports. It is marked by the buildup of a protein called p-tau in neurons around blood vessels in the sulci of the brain (Mayo Clinic, 2023); this damage is distinct from damage caused by aging or Alzheimer's. Similar to concussions, the negative effects are not being felt by athletes in real time and cannot be diagnosed objectively. In fact, CTE can only be diagnosed posthumously. People can live full lives without ever realizing that this condition was the cause of neurological issues they might be suffering from.  

    I first learned about this degenerative disease in 2024 after watching a docu-series about Aaron Hernandez, a young NFL player who was charged with murder. After his death, his brain was autopsied and was found to be severely damaged by CTE. The series explored the idea that Hernandez's severe neural degeneration is what caused him to engage in allegedly uncharacteristic violent behavior. This case, in tandem with others, led researchers to ask if there are any early symptoms of CTE. People who were confirmed to have CTE at autopsy were reported to have cognitive, behavioral, mood, and movement changes, but there are no confirmed early symptoms prior to diagnosis. 

    This question drove the research done by Morgane et al. at Boston University. These scientists studied what actually happens in the brains of athletes who experienced repeated head injuries (RHIs) before they develop CTE. They found that brain damage starts earlier than previously thought, not just after the p-tau protein builds up in the sulci. CTE is defined by the p-tau buildup, but it was found that neuron loss and inflammation occurred before tau even appeared (Morgane et al., 2025). The findings suggest that even non-concussive head traumas can cause the symptoms associated with CTE. With this research and further study, scientists may be able to develop early biomarkers and treatments that may be able to stop the progressions of these injuries. 

    So, while methods to diagnose and therapies to treat are still in development, what can athletes do to limit the frequencies of head traumas?

    Prevention strategies must begin with the regulations and rules that are in place for these heavy contact sports. Coaches can limit the amount of time spent tackling during practices, and they can also work to change tackling techniques. There can be ways to play the game well while keeping the players safe from long-term injury. Helmet and equipment standards can be improved as well and strictly enforced by sports officials. Youth sports teams must also be educated on what concussions are, how symptoms feel different to regular ailments, and when to speak up. Athletes must be informed of the consequences of not speaking up or understating their injuries. Proper education is important for timely intervention. 

    Awareness can lead to early recognition and proper management of head injuries, which will reduce the risk of long-term damage (IU Health, 2025). A combination of these things in addition to the work being done by researchers and scientists will put a good step forward in reliable concussion diagnosis and improved safety of athletes from degenerative brain disease.

References:

“How Athletes Can Prevent Head Injuries and Concussions in Sports.” IU Health, Indiana University Health, 19 Mar. 2025, iuhealth.org/thrive/how-athletes-can-prevent-head-injuries-and-concussions-in-sports.

Mayo Clinic. “Chronic Traumatic Encephalopathy - Symptoms and Causes.” Mayo Clinic, Mayo Clinic, 18 Nov. 2023, www.mayoclinic.org/diseases-conditions/chronic-traumatic-encephalopathy/symptoms-causes/syc-20370921

Morgane, Butler, et al. “Repeated Head Trauma Causes Neuron Loss and Inflammation in Young Athletes.” Nature, 17 Sept. 2025, pp. 1–10, www.nature.com/articles/s41586-025-09534-6, https://doi.org/10.1038/s41586-025-09534-6.

NIH. “Effects of Repeated Head Trauma in Young Athletes.” National Institutes of Health (NIH), 19 Nov. 2025, www.nih.gov/news-events/nih-research-matters/effects-repeated-head-trauma-young-athletes.

Smith, Dana G. “Many Minor Hits Can Damage an Athlete’s Brain, Studies Find.” The New York Times, 17 Sept. 2025, www.nytimes.com/2025/09/17/well/mind/brain-damage-sports.html.

W. Tad Archambault, and Dave Ellemberg. “Hard-Headed Decisions: Intrapersonal Factors Underlying Concussion Reporting in University Athletes.” Neurotrauma Reports, vol. 4, no. 1, 1 Aug. 2023, pp. 533–542, https://doi.org/10.1089/neur.2023.0030.

Kraus, Nina, et al. “Auditory Biological Marker of Concussion in Children.” Scientific Reports, vol. 6, no. 1, Dec. 2016, www.nature.com/articles/srep39009, https://doi.org/10.1038/srep39009. 

Nonverbal Behaviors: A Means of Communication

    Nonverbal behaviors, such as hand gestures, are a driving force in human communication that many often overlook as they just come naturally while speaking across cultures. Nonverbal behaviors can not only help increase language comprehension/retention, but also act as a way of communication across cultures and languages when language cannot. For example, some hand gestures that are universal across cultures and can be used to aid communication when language barriers are present. In the paper, “The Role of Visual Attention in Processing and Learning from Gesture,” by Elizabeth Wakefield this idea of the importance of co-speech gestures is explored, specifically including language comprehension in bilingual children.

    Wakefield’s research in this paper is focused on the impact of co-speech gestures in bilingual children, not of equal proficiencies in the two languages, and if gestures help the children understand and remember a narrative being told in their less proficient language compared to their more proficient language.  Techniques were used such as eye tracking to determine where the children were looking at the speaker while being told the narrative. From the results, it was found that co-speech gestures do help language comprehension: when being told the narrative in their less proficient language, the children were able to better recall the narratives when hand gestures were used. Along with the finding that co-speech hand gestures help language comprehension, from eye tracking, it was found that the children paid more attention to the hands of the speaker when listening to the language they are less proficient in. 

    With co-speech gestures being a part of communication that largely varies across cultures, the question can come up of how the cultural impact could alter the effectiveness of co-speech gestures as an aid in language comprehension? In a paper by Hio Tong Pang, Xiaolin Zhou, and Mingyuan Chu, “Cross-cultural Differences in Using Nonverbal Behaviors to Identify Indirect Replies,” it is investigated how different cultures interpret non-verbal behaviors in order to understand indirect replies. Indirect replies are use of language that hints at the meaning rather than just simply stating it. This study included both culturally British and Chinese individuals, and included the participants interpreting non-verbal gestures from their own and each other's cultures. The results found that British individuals were better at recognizing indirect replies from British individuals but struggled with indirect replies from Chinese individuals, while Chinese individuals were able to recognize indirect replies from both Chinese and British individuals. An important thing to note when interpreting these findings is a major cultural difference between the UK and China: that the UK is an individualistic society while China is a collectivist society. This can lead to the conclusion that Chinese individuals were better at decoding indirect replies due to being from a collectivist society rather than an individualistic society like the British individuals. 

    These two studies reveal that co-speech gestures can not just help people communicate across languages, but also cultures. In a multi-cultural world, co-speech gestures make it capable to communicate where words cannot. Recognition and understanding of nonverbal gestures is something that varies across cultures, but they hold the power to aid in communication across all. 

References

Zielinski, N., & Wakefield, E. M. (2021). Language Proficiency Impacts the Benefits of Co-Speech Gesture for Narrative Understanding Through a Visual Attention Mechanism. 2101-2107. Paper presented at 43rd Annual Meeting of the Cognitive Science Society: Comparative Cognition: Animal Minds, CogSci 2021, Virtual, Online, Austria.

Pang, H.T., Zhou, X. & Chu, M. Cross-cultural Differences in Using Nonverbal Behaviors to Identify Indirect Replies. J Nonverbal Behav 48, 323–344 (2024).

https://doi.org/10.1007/s10919-024-00454-z