1
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Magara F, Boury-Jamot B. About statistical significance, and the lack thereof. Lab Anim 2024:236772241248509. [PMID: 39157984 DOI: 10.1177/00236772241248509] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 08/20/2024]
Abstract
Absence of statistical significance (i.e., p > 0.05) in the results of a frequentist test comparing two samples is often used as evidence of absence of difference, or absence of effect of a treatment, on the measured variable. Such conclusions are often wrong because absence of significance may merely result from a sample size that is too small to reveal an effect. To conclude that there is no meaningful effect of a treatment/condition, it is necessary to use an appropriate statistical approach. For frequentist statistics, a simple tool for this goal is the 'two one-sided t-test,' a form of equivalence test that relies on the a priori definition of a minimal difference considered to be relevant. In other words, the smallest effect size of interest should be established in advance. We present the principles of this test and give examples where it allows correct interpretation of the results of a classical t-test assuming absence of difference. Equivalence tests are also very useful in probing whether certain significant results are also biologically meaningful, because when comparing large samples it is possible to find significant results in both an equivalence test and in a two-sample t-test, assuming no difference as the null hypothesis.
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Affiliation(s)
- Fulvio Magara
- Dept of Psychiatry, Center for Psychiatric Neurosciences, Lausanne University Hospital, Switzerland
| | - Benjamin Boury-Jamot
- Dept of Psychiatry, Center for Psychiatric Neurosciences, Lausanne University Hospital, Switzerland
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2
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Nakagawa S, Lagisz M. Next steps after airing disagreement on a scientific issue with policy implications: a meta-analysis, multi-lab replication and adversarial collaboration. BMC Biol 2023; 21:116. [PMID: 37217976 DOI: 10.1186/s12915-023-01567-5] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2023] [Accepted: 03/16/2023] [Indexed: 05/24/2023] Open
Abstract
Canadian policymakers are interested in determining whether farmed Atlantic salmon, frequently infected with Piscine orthoreovirus (PRV), may threaten wild salmon populations in the Pacific Northwest. A relevant work has been published in BMC Biology by Polinksi and colleagues, but their conclusion that PRV has a negligible impact on the energy expenditure and respiratory performance of sockeye salmon is disputed by Mordecai and colleagues, whose re-analysis is presented in a correspondence article. So, what is the true effect and what should follow this unresolved dispute? We suggest a 'registered multi-lab replication with adversaries'.
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Affiliation(s)
- Shinichi Nakagawa
- Evolution & Ecology Research Centre and School of Biological, Earth and Environmental Sciences, University of New South Wales, Sydney, NSW, 2052, Australia.
- Theoretical Sciences Visiting Program, Okinawa Institute of Science and Technology Graduate University, Onna, 904-0495, Japan.
| | - Malgorzata Lagisz
- Evolution & Ecology Research Centre and School of Biological, Earth and Environmental Sciences, University of New South Wales, Sydney, NSW, 2052, Australia
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3
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Farrar BG, Vernouillet A, Garcia-Pelegrin E, Legg EW, Brecht KF, Lambert PJ, Elsherif M, Francis S, O'Neill L, Clayton NS, Ostojić L. Reporting and interpreting non-significant results in animal cognition research. PeerJ 2023; 11:e14963. [PMID: 36919170 PMCID: PMC10008313 DOI: 10.7717/peerj.14963] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2022] [Accepted: 02/06/2023] [Indexed: 03/11/2023] Open
Abstract
How statistically non-significant results are reported and interpreted following null hypothesis significance testing is often criticized. This issue is important for animal cognition research because studies in the field are often underpowered to detect theoretically meaningful effect sizes, i.e., often produce non-significant p-values even when the null hypothesis is incorrect. Thus, we manually extracted and classified how researchers report and interpret non-significant p-values and examined the p-value distribution of these non-significant results across published articles in animal cognition and related fields. We found a large amount of heterogeneity in how researchers report statistically non-significant p-values in the result sections of articles, and how they interpret them in the titles and abstracts. Reporting of the non-significant results as "No Effect" was common in the titles (84%), abstracts (64%), and results sections (41%) of papers, whereas reporting of the results as "Non-Significant" was less common in the titles (0%) and abstracts (26%), but was present in the results (52%). Discussions of effect sizes were rare (<5% of articles). A p-value distribution analysis was consistent with research being performed with low power of statistical tests to detect effect sizes of interest. These findings suggest that researchers in animal cognition should pay close attention to the evidence used to support claims of absence of effects in the literature, and-in their own work-report statistically non-significant results clearly and formally correct, as well as use more formal methods of assessing evidence against theoretical predictions.
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Affiliation(s)
- Benjamin G Farrar
- Department of Psychology, University of Cambridge, Cambridge, United Kingdom.,Institute for Globally Distributed Open Research and Education (IGDORE), Cambridge, United Kingdom
| | | | - Elias Garcia-Pelegrin
- Department of Psychology, University of Cambridge, Cambridge, United Kingdom.,Department of Psychology, National University of Singapore, Singapore, Singapore
| | - Edward W Legg
- Department of Psychology, Faculty of Humanities and Social Sciences, University of Rijeka, Rijeka, Croatia.,Division of Cognitive Sciences, University of Rijeka, Rijeka, Croatia.,Centre for Mind and Behaviour, University of Rijeka, Rijeka, Croatia
| | | | - Poppy J Lambert
- Messerli Research Insititute, University of Vienna, Vienna, Austria
| | - Mahmoud Elsherif
- Department of Psychology, University of Birmingham, Birmingham, United Kingdom.,University of Leicester, Leicester, United Kingdom
| | - Shannon Francis
- Comparative Cognition Research Group, Max Planck Institute for Ornithology, Seewiesen, Germany
| | - Laurie O'Neill
- Comparative Cognition Research Group, Max Planck Institute for Ornithology, Seewiesen, Germany
| | - Nicola S Clayton
- Department of Psychology, University of Cambridge, Cambridge, United Kingdom
| | - Ljerka Ostojić
- Department of Psychology, Faculty of Humanities and Social Sciences, University of Rijeka, Rijeka, Croatia.,Division of Cognitive Sciences, University of Rijeka, Rijeka, Croatia.,Centre for Mind and Behaviour, University of Rijeka, Rijeka, Croatia
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4
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Leitão AV, Mulder RA, Hall ML. Song functions for joint territory defence and within-pair communication in female and male lovely fairy-wrens. Anim Behav 2022. [DOI: 10.1016/j.anbehav.2022.08.003] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/01/2022]
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5
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Rose EM, Haakenson CM, Stennette K, Patel A, Gaind S, Shank BD, Madison FN, Ball GF. Neuroendocrine and behavioral response to testosterone-induced female song in canaries (Serinus canaria). Physiol Behav 2022; 250:113782. [PMID: 35314175 PMCID: PMC10544658 DOI: 10.1016/j.physbeh.2022.113782] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2021] [Revised: 02/22/2022] [Accepted: 03/17/2022] [Indexed: 11/24/2022]
Abstract
Male song in songbirds is a critical and elaborate signal for mate attraction. In many species female listeners respond to male song both behaviorally and physiologically (e.g. copulation solicitation displays and production of the immediate early gene ZENK in auditory regions). It is becoming increasingly well known that females in many species also sing. However, in common lab species, such as canaries (Serinus canaria), female song is limited and has been primarily studied in the context of administering of exogenous testosterone (T) to increase song rate and length. In this study we addressed to what extent female canary songs are masculinized by the administration of exogenous T based on the behavioral and physiological responses of avian receivers. Specifically, are T induced female songs sufficient to elicit courtship behaviors and auditory ZENK expression in female listeners? We found that female songs after 3 weeks of exogenous T were significantly longer and more complex than female songs after 12 weeks of exogenous T. Additionally, we found that playback of 3-week T song significantly increased sexual response behaviors and the expression of ZENK in the auditory brain regions of female listeners. Finally, we conclude that extended periods of T do not necessarily maintain the masculinization of female song.
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Affiliation(s)
- Evangeline M Rose
- Department of Psychology, University of Maryland, College Park MD, USA; Program in Neuroscience and Cognitive Science, University of Maryland, College Park, MD, USA.
| | - Chelsea M Haakenson
- Department of Psychology, University of Maryland, College Park MD, USA; Program in Neuroscience and Cognitive Science, University of Maryland, College Park, MD, USA
| | | | - Aliyah Patel
- Department of Psychology, University of Maryland, College Park MD, USA
| | - Shivika Gaind
- Department of Psychology, University of Maryland, College Park MD, USA
| | | | - Farrah N Madison
- Department of Psychology, University of Maryland, College Park MD, USA; Department of Biology, Hope College, Holland, MI, USA
| | - Gregory F Ball
- Department of Psychology, University of Maryland, College Park MD, USA; Program in Neuroscience and Cognitive Science, University of Maryland, College Park, MD, USA
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6
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Rose EM, Haakenson CM, Ball GF. Sex differences in seasonal brain plasticity and the neuroendocrine regulation of vocal behavior in songbirds. Horm Behav 2022; 142:105160. [PMID: 35366412 DOI: 10.1016/j.yhbeh.2022.105160] [Citation(s) in RCA: 16] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/01/2021] [Revised: 03/11/2022] [Accepted: 03/14/2022] [Indexed: 11/20/2022]
Abstract
Birdsong is controlled in part by a discrete network of interconnected brain nuclei regulated in turn by steroid hormones and environmental stimuli. This complex interaction results in neural changes that occur seasonally as the environment varies (e.g., photoperiod, food/water availability, etc.). Variation in environment, vocal behavior, and neuroendocrine control has been primarily studied in male songbirds in both laboratory studies of captive birds and field studies of wild caught birds. The bias toward studying seasonality in the neuroendocrine regulation of song in male birds comes from a historic focus on sexually selected male behaviors. In fact, given that male song is often loud and accompanied by somewhat extravagant courtship behaviors, female song has long been overlooked. To compound this bias, the primary model songbird species for studies in the lab, zebra finches (Taeniopygia guttata) and canaries (Serinus canaria), exhibit little or no female song. Therefore, understanding the degree of variation and neuroendocrine control of seasonality in female songbirds is a major gap in our knowledge. In this review, we discuss the importance of studying sex differences in seasonal plasticity and the song control system. Specifically, we discuss sex differences in 1) the neuroanatomy of the song control system, 2) the distribution of receptors for androgens and estrogens and 3) the seasonal neuroplasticity of the hypothalamo-pituitary-gonadal axis as well as in the neural and cellular mechanisms mediating song system changes. We also discuss how these neuroendocrine mechanisms drive sex differences in seasonal behavior. Finally, we highlight specific gaps in our knowledge and suggest experiments critical for filling these gaps.
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Affiliation(s)
- Evangeline M Rose
- Department of Psychology, University of Maryland, College Park, MD, USA; Program in Neuroscience and Cognitive Science, University of Maryland, College Park, MD, USA.
| | - Chelsea M Haakenson
- Department of Psychology, University of Maryland, College Park, MD, USA; Program in Neuroscience and Cognitive Science, University of Maryland, College Park, MD, USA
| | - Gregory F Ball
- Department of Psychology, University of Maryland, College Park, MD, USA; Program in Neuroscience and Cognitive Science, University of Maryland, College Park, MD, USA
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7
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Rouse ML. Where to from here? Perspectives on steroid-induced and naturally-occurring singing in female songbirds. Horm Behav 2022; 138:105098. [PMID: 34902757 DOI: 10.1016/j.yhbeh.2021.105098] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/01/2021] [Revised: 11/14/2021] [Accepted: 11/22/2021] [Indexed: 02/01/2023]
Abstract
In many species, male and female animals differ in the types and frequency of particular behaviors (e.g. reproductive behavior, parental behavior, etc.). These differences in behavior are quite often related to the neural and hormonal control of said behaviors. In the temperate zone it is commonly stated that male songbirds sing much more frequently and with much greater quality compared to their female counterparts. However, recent evidence has called these claims into question (Odom et al., 2014; Price et al., 2008; Webb et al., 2016). That said, neuroendocrine studies of song behavior have primarily focused on male birds and relatively little work has been done exclusively or comparatively with female songbirds. What we do know, however, is that there is wide variability in the vocal ability and capacity of female songbirds and that there is a developmental link between the hormonal milieu and neuro-social development that facilitate these behavioral phenotypes. Both testosterone and estradiol have been demonstrated to play pivotal roles in behavioral and neural differentiation of male and female song behavior profiles. Here we review a brief history of empirical investigation into steroid regulation of song in female birds, including the pattern of song activation, constraints on the ability of testosterone to induce singing, and the role of the anterior forebrain in supporting song learning. We conclude with a brief analysis of a major gap in the field's knowledge regarding naturally occurring female song and the neuroendocrine underpinnings of a socially salient learned behavior ripe for systematic investigation.
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Affiliation(s)
- Melvin L Rouse
- Department of Psychology, University of Puget Sound, Tacoma, WA, USA.
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8
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Benedict L, Hardt B, Dargis L. Form and Function Predict Acoustic Transmission Properties of the Songs of Male and Female Canyon Wrens. Front Ecol Evol 2021. [DOI: 10.3389/fevo.2021.722967] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
To function effectively, animal signals must transmit through the environment to receivers, and signal transmission properties depend on signal form. Here we investigated how the transmission of multiple parts of a well-studied signal, bird song, varies between males and females of one species. We hypothesized that male and female songs would have different transmission properties, reflecting known differences in song form and function. We further hypothesized that two parts of male song used differentially in broadcast singing and aggressive contests would transmit differently. Analyses included male and female songs from 20 pairs of canyon wrens (Catherpes mexicanus) played and re-recorded in species-typical habitat. We found that male song cascades used in broadcast singing propagated farther than female songs, with higher signal-to-noise ratios at distance. In contrast, we demonstrated relatively restricted propagation of the two vocalization types typically used in short-distance aggressive signaling, female songs and male “cheet” notes. Of the three tested signals, male “cheet” notes had the shortest modeled propagation distances. Male and female signals blurred similarly, with variable patterns of excess attenuation. Both male song parts showed more consistent transmission across the duration of the signal than did female songs. Song transmission, thus, varied by sex and reflected signal form and use context. Results support the idea that males and females of the same species can show distinctly different signal evolution trajectories. Sexual and social selection pressures can shape sex-specific signal transmission, even when males and females are communicating in shared physical environments.
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9
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Rose EM, Prior NH, Ball GF. The singing question: re-conceptualizing birdsong. Biol Rev Camb Philos Soc 2021; 97:326-342. [PMID: 34609054 DOI: 10.1111/brv.12800] [Citation(s) in RCA: 18] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2021] [Revised: 09/21/2021] [Accepted: 09/22/2021] [Indexed: 01/31/2023]
Abstract
Birdsong has been the subject of broad research from a variety of sub-disciplines and has taught us much about the evolution, function, and mechanisms driving animal communication and cognition. Typically, birdsong refers to the specialized vocalizations produced by oscines. Historically, much of the research on birdsong was conducted in north temperate regions (specifically in Europe and North America) leading to multiple biases. Due to these historic biases these vocalizations are generally considered to be highly sexually dimorphic, heavily shaped by sexual selection and essential for courtship and territoriality. Song is also typically defined as a learned trait shaped by cultural evolution. Together, this framework focuses research specifically on males, particularly during the north temperate breeding season - reflecting and thereby reinforcing this framework. The physiological underpinnings of song often emphasize the role of the hypothalamic-pituitary-gonadal axis (associated with breeding changes) and the song control system (underlying vocal learning). Over the years there has been great debate over which features of song are essential to the definition of birdsong, which features apply broadly to contexts outside males in the north temperate region, and over the importance of having a definition at all. Importantly, the definitions we use can both guide and limit the progress of research. Here, we describe the history of these definitions, and how these definitions have directed and restricted research to focus on male song in sexually selected contexts. Additionally, we highlight the gaps in our scientific knowledge, especially with respect to the function and physiological mechanisms underlying song in females and in winter, as well as in non-seasonally breeding species. Furthermore, we highlight the problems with using complexity and learning as dichotomous variables to categorize songs and calls. Across species, no one characteristic of song - sexual dimorphism, seasonality, complexity, sexual selection, learning - consistently delineates song from other songbird vocal communication. We provide recommendations for next steps to build an inclusive information framework that will allow researchers to explore nuances in animal communication and promote comparative research. Specifically, we recommend that researchers should operationalize the axis of variation most relevant to their study/species by identifying their specific question and the variable(s) of focus (e.g. seasonality). Researchers should also identify the axis (axes) of variation (e.g. degree of control by testosterone) most relevant to their study and use language consistent with the question and axis (axes) of variation (e.g. control by testosterone in the seasonal vocal production of birds).
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Affiliation(s)
- Evangeline M Rose
- Department of Psychology, University of Maryland, College Park, 4094 Campus Dr., College Park, MD, 20742, U.S.A.,Program in Neuroscience and Cognitive Science, University of Maryland, College Park, 0219 Cole Student Activities Building, 4090 Union Drive, College Park, MD, 20742, U.S.A
| | - Nora H Prior
- Department of Psychology, University of Maryland, College Park, 4094 Campus Dr., College Park, MD, 20742, U.S.A.,Program in Neuroscience and Cognitive Science, University of Maryland, College Park, 0219 Cole Student Activities Building, 4090 Union Drive, College Park, MD, 20742, U.S.A
| | - Gregory F Ball
- Department of Psychology, University of Maryland, College Park, 4094 Campus Dr., College Park, MD, 20742, U.S.A.,Program in Neuroscience and Cognitive Science, University of Maryland, College Park, 0219 Cole Student Activities Building, 4090 Union Drive, College Park, MD, 20742, U.S.A
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10
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Wearable sensor-driven responsive deep brain stimulation for essential tremor. Brain Stimul 2021; 14:1434-1443. [PMID: 34547503 DOI: 10.1016/j.brs.2021.09.002] [Citation(s) in RCA: 23] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2021] [Revised: 08/28/2021] [Accepted: 09/11/2021] [Indexed: 10/20/2022] Open
Abstract
BACKGROUND Deep brain stimulation (DBS) is an effective surgical therapy for individuals with essential tremor (ET). However, DBS operates continuously, resulting in adverse effects such as postural instability or dysarthria. Continuous DBS (cDBS) also presents important practical issues including limited battery life of the implantable neurostimulator (INS). Collectively, these shortcomings impact optimal therapeutic benefit in ET. OBJECTIVE The goal of the study was to establish a physiology-driven responsive DBS (rDBS) system to provide targeted and personalized therapy based on electromyography (EMG) signals. METHODS Ten participants with ET underwent rDBS using Nexus-D, a Medtronic telemetry wand that acts as a direct conduit to the INS by modulating stimulation voltage. Two different rDBS paradigms were tested: one driven by one EMG (single-sensor) and another driven by two or more EMGs (multi-sensor). The feature(s) used in the rDBS algorithms was the pow2er in the participant's tremor frequency band derived from the sensors controlling stimulation. Both algorithms were trained on kinetic and postural data collected during DBS off and cDBS states. RESULTS Using established clinical scales and objective measurements of tremor severity, we confirm that both rDBS paradigms deliver equivalent clinical benefit as cDBS. Moreover, both EMG-driven rDBS paradigms delivered less total electrical energy translating to an increase in the battery life of the INS. CONCLUSIONS The results of this study verify that EMG-driven rDBS provides clinically equivalent tremor suppression compared to cDBS, while delivering less total electrical energy. Controlling stimulation using a dynamic rDBS paradigm can mitigate limitations of traditional cDBS systems.
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11
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Lipshutz SE, Rosvall KA. Nesting strategy shapes territorial aggression but not testosterone: A comparative approach in female and male birds. Horm Behav 2021; 133:104995. [PMID: 34000663 DOI: 10.1016/j.yhbeh.2021.104995] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/19/2020] [Revised: 03/19/2021] [Accepted: 04/29/2021] [Indexed: 11/21/2022]
Abstract
Our understanding of the proximate and ultimate mechanisms shaping competitive reproductive phenotypes primarily stems from research on male-male competition for mates, even though competition is widespread in both sexes. We evaluate the hypothesis that the restricted nature of a resource required for reproduction, i.e. nest site, is a key variable driving territorial competition and testosterone secretion in female and male birds. Obligate secondary cavity-nesting has evolved repeatedly across avian lineages, providing a useful comparative context to explore how competition over limited nest cavities shapes aggression and its underlying mechanisms across species. Although evidence from one or another cavity-nesting species suggests that territorial aggression is adaptive in both females and males, this has not yet been tested in a comparative framework. We predicted that cavity-nesting generates more robust territorial aggression, in comparison to close relatives with less restrictive nesting strategies. Our focal species were two obligate secondary cavity-nesting species and two related species with more flexible nesting strategies in the same avian family: tree swallow (Tachycineta bicolor) vs. barn swallow (Hirundo rustica); Eastern bluebird (Sialia sialis) vs. American robin (Turdus migratorius). We assayed conspecific aggression using simulated territorial intrusion and found that cavity-nesting species displayed greater territorial aggression than their close relatives. This pattern held for both females and males. Because territorial aggression is often associated with elevated testosterone, we also hypothesized that cavity-nesting species would exhibit higher testosterone levels in circulation. However, cavity-nesting species did not have higher testosterone in circulation for either sex, despite some correlative evidence that testosterone is associated with higher rates of physical attack in female tree swallows. Our focus on a context that is relevant to both sexes - competition over essential breeding resources - provides a useful framework for co-consideration of proximate and ultimate drivers of reproductive competition in females and males.
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Affiliation(s)
- Sara E Lipshutz
- Department of Biology, Indiana University, Bloomington, IN 47405, USA.
| | - Kimberly A Rosvall
- Department of Biology, Indiana University, Bloomington, IN 47405, USA; Center for the Integrative Study of Animal Behavior, Indiana University, Bloomington, IN 47405, USA
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12
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Opri E, Cernera S, Molina R, Eisinger RS, Cagle JN, Almeida L, Denison T, Okun MS, Foote KD, Gunduz A. Chronic embedded cortico-thalamic closed-loop deep brain stimulation for the treatment of essential tremor. Sci Transl Med 2021; 12:12/572/eaay7680. [PMID: 33268512 DOI: 10.1126/scitranslmed.aay7680] [Citation(s) in RCA: 61] [Impact Index Per Article: 20.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2019] [Revised: 01/14/2020] [Accepted: 08/25/2020] [Indexed: 11/02/2022]
Abstract
Deep brain stimulation (DBS) is an approved therapy for the treatment of medically refractory and severe movement disorders. However, most existing neurostimulators can only apply continuous stimulation [open-loop DBS (OL-DBS)], ignoring patient behavior and environmental factors, which consequently leads to an inefficient therapy, thus limiting the therapeutic window. Here, we established the feasibility of a self-adjusting therapeutic DBS [closed-loop DBS (CL-DBS)], fully embedded in a chronic investigational neurostimulator (Activa PC + S), for three patients affected by essential tremor (ET) enrolled in a longitudinal (6 months) within-subject crossover protocol (DBS OFF, OL-DBS, and CL-DBS). Most patients with ET experience involuntary limb tremor during goal-directed movements, but not during rest. Hence, the proposed CL-DBS paradigm explored the efficacy of modulating the stimulation amplitude based on patient-specific motor behavior, suppressing the pathological tremor on-demand based on a cortical electrode detecting upper limb motor activity. Here, we demonstrated how the proposed stimulation paradigm was able to achieve clinical efficacy and tremor suppression comparable with OL-DBS in a range of movements (cup reaching, proximal and distal posture, water pouring, and writing) while having a consistent reduction in energy delivery. The proposed paradigm is an important step toward a behaviorally modulated fully embedded DBS system, capable of delivering stimulation only when needed, and potentially mitigating pitfalls of OL-DBS, such as DBS-induced side effects and premature device replacement.
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Affiliation(s)
- Enrico Opri
- J. Crayton Pruitt Family Department of Biomedical Engineering, University of Florida, Gainesville, FL 32611, USA.
| | - Stephanie Cernera
- J. Crayton Pruitt Family Department of Biomedical Engineering, University of Florida, Gainesville, FL 32611, USA
| | - Rene Molina
- Electrical and Computer Engineering, University of Florida, Gainesville, FL 32603, USA
| | - Robert S Eisinger
- Norman Fixel Institute for Neurological Diseases at UF Health, Departments of Neurology and Neurosurgery, University of Florida, Gainesville, FL 32608, USA
| | - Jackson N Cagle
- J. Crayton Pruitt Family Department of Biomedical Engineering, University of Florida, Gainesville, FL 32611, USA
| | - Leonardo Almeida
- Norman Fixel Institute for Neurological Diseases at UF Health, Departments of Neurology and Neurosurgery, University of Florida, Gainesville, FL 32608, USA
| | - Timothy Denison
- Department of Engineering Science, University of Oxford, Oxford OX1 3PJ, UK
| | - Michael S Okun
- Norman Fixel Institute for Neurological Diseases at UF Health, Departments of Neurology and Neurosurgery, University of Florida, Gainesville, FL 32608, USA
| | - Kelly D Foote
- Norman Fixel Institute for Neurological Diseases at UF Health, Departments of Neurology and Neurosurgery, University of Florida, Gainesville, FL 32608, USA
| | - Aysegul Gunduz
- J. Crayton Pruitt Family Department of Biomedical Engineering, University of Florida, Gainesville, FL 32611, USA.,Electrical and Computer Engineering, University of Florida, Gainesville, FL 32603, USA.,Norman Fixel Institute for Neurological Diseases at UF Health, Departments of Neurology and Neurosurgery, University of Florida, Gainesville, FL 32608, USA
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13
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Austin VI, Dalziell AH, Langmore NE, Welbergen JA. Avian vocalisations: the female perspective. Biol Rev Camb Philos Soc 2021; 96:1484-1503. [PMID: 33797176 DOI: 10.1111/brv.12713] [Citation(s) in RCA: 18] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2020] [Revised: 03/16/2021] [Accepted: 03/17/2021] [Indexed: 01/04/2023]
Abstract
Research on avian vocalisations has traditionally focused on male song produced by oscine passerines. However, accumulating evidence indicates that complex vocalisations can readily evolve outside the traditional contexts of mate attraction and territory defence by male birds, and yet the previous bias towards male song has shaped - and continues to shape - our understanding of avian communication as a whole. Accordingly, in this review we seek to address this imbalance by synthesising studies on female vocalisations from across signalling contexts throughout the Aves, and discuss the implications of recent empirical advances for our understanding of vocalisations in both sexes. This review reveals great structural and functional diversity among female vocalisations and highlights the important roles that vocalisations can play in mediating female-specific behaviours. However, fundamental gaps remain. While there are now several case studies that identify the function of female vocalisations, few quantify the associated fitness benefits. Additionally, very little is known about the role of vocal learning in the development of female vocalisations. Thus, there remains a pressing need to examine the function and development of all forms of vocalisations in female birds. In the light of what we now know about the functions and mechanisms of female vocalisations, we suggest that conventional male-biased definitions of songs and calls are inadequate for furthering our understanding of avian vocal communication more generally. Therefore, we propose two simple alternatives, both emancipated from the sex of the singer. The first distinguishes song from calls functionally as a sexually selected vocal signal, whilst the second distinguishes them mechanistically in terms of their underlying neurological processes. It is clear that more investigations are needed into the ultimate and proximate causes of female vocalisations; however, these are essential if we are to develop a holistic epistemology of avian vocal communication in both sexes, across ecological contexts and taxonomic divides.
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Affiliation(s)
- Victoria I Austin
- Hawkesbury Institute for the Environment, Western Sydney University, Hawkesbury Campus, Ground Floor, Building R2, Locked Bag 1797, Penrith, NSW, 2751, Australia
| | - Anastasia H Dalziell
- Hawkesbury Institute for the Environment, Western Sydney University, Hawkesbury Campus, Ground Floor, Building R2, Locked Bag 1797, Penrith, NSW, 2751, Australia.,Centre for Sustainable Ecosystem Solutions, School of Earth, Atmospheric and Life Sciences, University of Wollongong, Northfields Ave, Wollongong, NSW, 2522, Australia.,Cornell Lab of Ornithology, Cornell University, 159 Sapsucker Woods Rd., Ithaca, NY, 14850, U.S.A
| | - Naomi E Langmore
- Research School of Biology, The Australian National University, 46 Sullivan's Creek Road, Acton, Canberra, ACT, 2601, Australia
| | - Justin A Welbergen
- Hawkesbury Institute for the Environment, Western Sydney University, Hawkesbury Campus, Ground Floor, Building R2, Locked Bag 1797, Penrith, NSW, 2751, Australia
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14
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Vitevitch MS, Ng JW, Hatley E, Castro N. Phonological but not semantic influences on the speech-to-song illusion. Q J Exp Psychol (Hove) 2021; 74:585-597. [PMID: 33089742 PMCID: PMC8287799 DOI: 10.1177/1747021820969144] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
In the speech to song illusion, a spoken phrase begins to sound as if it is being sung after several repetitions. Castro et al. (2018) used Node Structure Theory (NST; MacKay, 1987), a model of speech perception and production, to explain how the illusion occurs. Two experiments further test the mechanisms found in NST-priming, activation, and satiation-as an account of the speech to song illusion. In Experiment 1, words varying in the phonological clustering coefficient influenced how quickly a lexical node could recover from satiation, thereby influencing the song-like ratings to lists of words that were high versus low in phonological clustering coefficient. In Experiment 2, we used equivalence testing (i.e., the TOST procedure) to demonstrate that once lexical nodes are satiated the higher level semantic information associated with the word cannot differentially influence song-like ratings to lists of words varying in emotional arousal. The results of these two experiments further support the NST account of the speech to song illusion.
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15
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Campbell H, Lakens D. Can we disregard the whole model? Omnibus non-inferiority testing for R 2 in multi-variable linear regression and η̂2 in ANOVA. THE BRITISH JOURNAL OF MATHEMATICAL AND STATISTICAL PSYCHOLOGY 2021; 74:64-89. [PMID: 32056209 DOI: 10.1111/bmsp.12201] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/06/2019] [Revised: 01/08/2020] [Indexed: 06/10/2023]
Abstract
Determining a lack of association between an outcome variable and a number of different explanatory variables is frequently necessary in order to disregard a proposed model (i.e., to confirm the lack of a meaningful association between an outcome and predictors). Despite this, the literature rarely offers information about, or technical recommendations concerning, the appropriate statistical methodology to be used to accomplish this task. This paper introduces non-inferiority tests for ANOVA and linear regression analyses, which correspond to the standard widely used F test for η̂2 and R2 , respectively. A simulation study is conducted to examine the Type I error rates and statistical power of the tests, and a comparison is made with an alternative Bayesian testing approach. The results indicate that the proposed non-inferiority test is a potentially useful tool for 'testing the null'.
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Affiliation(s)
- Harlan Campbell
- Department of Statistics, University of British Columbia, Vancouver, British Columbia, Canada
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16
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Sikora JG, Moyer MJ, Omland KE, Rose EM. Large female song repertoires and within‐pair song type sharing in a temperate breeding songbird. Ethology 2020. [DOI: 10.1111/eth.13115] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Affiliation(s)
- Jonathan G. Sikora
- Department of Biological Sciences University of MarylandBaltimore County Baltimore MD USA
| | - Michelle J. Moyer
- Department of Biological Sciences University of MarylandBaltimore County Baltimore MD USA
| | - Kevin E. Omland
- Department of Biological Sciences University of MarylandBaltimore County Baltimore MD USA
| | - Evangeline M. Rose
- Department of Biological Sciences University of MarylandBaltimore County Baltimore MD USA
- Department of Psychology University of Maryland, College Park College Park MD USA
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17
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Smith RJ. P > .05: The incorrect interpretation of "not significant" results is a significant problem. AMERICAN JOURNAL OF PHYSICAL ANTHROPOLOGY 2020; 172:521-527. [PMID: 32570289 DOI: 10.1002/ajpa.24092] [Citation(s) in RCA: 21] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/02/2019] [Revised: 04/28/2020] [Accepted: 05/18/2020] [Indexed: 11/09/2022]
Abstract
Statistically nonsignificant (p > .05) results from a null hypothesis significance test (NHST) are often mistakenly interpreted as evidence that the null hypothesis is true-that there is "no effect" or "no difference." However, many of these results occur because the study had low statistical power to detect an effect. Power below 50% is common, in which case a result of no statistical significance is more likely to be incorrect than correct. The inference of "no effect" is not valid even if power is high. NHST assumes that the null hypothesis is true; p is the probability of the data under the assumption that there is no effect. A statistical test cannot confirm what it assumes. These incorrect statistical inferences could be eliminated if decisions based on p values were replaced by a biological evaluation of effect sizes and their confidence intervals. For a single study, the observed effect size is the best estimate of the population effect size, regardless of the p value. Unlike p values, confidence intervals provide information about the precision of the observed effect. In the biomedical and pharmacology literature, methods have been developed to evaluate whether effects are "equivalent," rather than zero, as tested with NHST. These methods could be used by biological anthropologists to evaluate the presence or absence of meaningful biological effects. Most of what appears to be known about no difference or no effect between sexes, between populations, between treatments, and other circumstances in the biological anthropology literature is based on invalid statistical inference.
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Affiliation(s)
- Richard J Smith
- Department of Anthropology, Washington University in St. Louis, St. Louis, Missouri, USA
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18
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Female song in eastern bluebirds varies in acoustic structure according to social context. Behav Ecol Sociobiol 2020. [DOI: 10.1007/s00265-020-2824-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
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19
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Rose EM, Coss DA, Haines CD, Danquah SA, Studds CE, Omland KE. Why do females sing?—pair communication and other song functions in eastern bluebirds. Behav Ecol 2019. [DOI: 10.1093/beheco/arz130] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
Abstract
Female bird song has been underappreciated and understudied, especially in temperate species. Birdsong was originally thought to be a trait used primarily by male songbirds for mate attraction and male/male contest. However, ornithologists have long known that females sing in many tropical songbirds, often for similar functions to male song. Yet, studies of female song in temperate regions remain scarce. Increasing our understanding of the function of female song in temperate species is a powerful step towards discerning the selective pressures that maintain elaborate female signals. In the last few decades, studies of temperate species have highlighted five major functional categories of female song. Using a modeling framework, based on all known functions of song in other species, we tested the function of female song in eastern bluebirds. The modeling framework allowed us to test the effect of multiple complex behaviors simultaneously to predict female song function. Additionally, modeling mitigated issues of multiple testing across the five different functional categories. We found that female song in eastern bluebirds is primarily used in pair communication. Specifically, females sing to strengthen and maintain long-term pair bonds. Strengthening pair-bonds may be advantageous for eastern bluebirds as pairs that remain together between nesting attempts and between years have higher reproductive success. We demonstrate a clear link between the function of female song in pair communication and the likely selective force of long-term pair bonds acting on eastern bluebird reproductive success. Additionally, our study highlights a major function of female song in a temperate species.
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Affiliation(s)
- Evangeline M Rose
- Department of Biological Sciences, University of Maryland, Baltimore County, Baltimore, MD, USA
| | - Derek A Coss
- Department of Biological Sciences, University of Maryland, Baltimore County, Baltimore, MD, USA
- Department of Biological Sciences, Salisbury University, Salisbury, MD, USA
| | - Casey D Haines
- Department of Biological Sciences, University of Maryland, Baltimore County, Baltimore, MD, USA
| | - Sheridan A Danquah
- Department of Biological Sciences, University of Maryland, Baltimore County, Baltimore, MD, USA
| | - Colin E Studds
- Department of Geography and Environmental Systems, University of Maryland, Baltimore County, Baltimore, MD, USA
| | - Kevin E Omland
- Department of Biological Sciences, University of Maryland, Baltimore County, Baltimore, MD, USA
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20
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Riebel K, Odom KJ, Langmore NE, Hall ML. New insights from female bird song: towards an integrated approach to studying male and female communication roles. Biol Lett 2019; 15:20190059. [PMID: 30940020 PMCID: PMC6501358 DOI: 10.1098/rsbl.2019.0059] [Citation(s) in RCA: 59] [Impact Index Per Article: 11.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2019] [Accepted: 03/13/2019] [Indexed: 11/12/2022] Open
Abstract
Historically, bird song has been regarded as a sex-specific signalling trait; males sing to attract females and females drive the evolution of signal exaggeration by preferring males with ever more complex songs. This view provides no functional role for female song. Historic geographical research biases generalized pronounced sex differences of phylogenetically derived northern temperate zone songbirds to all songbirds. However, we now know that female song is common and that both sexes probably sang in the ancestor of modern songbirds. This calls for research on adaptive explanations and mechanisms regulating female song, and a reassessment of questions and approaches to identify selection pressures driving song elaboration in both sexes and subsequent loss of female song in some clades. In this short review and perspective we highlight newly emerging questions and propose a research framework to investigate female song and song sex differences across species. We encourage experimental tests of mechanism, ontogeny, and function integrated with comparative evolutionary analyses. Moreover, we discuss the wider implications of female bird song research for our understanding of male and female communication roles.
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Affiliation(s)
- Katharina Riebel
- Institute of Biology, Leiden University, 2333 BE, Leiden, The Netherlands
| | - Karan J. Odom
- Institute of Biology, Leiden University, 2333 BE, Leiden, The Netherlands
- Cornell Lab of Ornithology and Department of Neurobiology and Behavior, Cornell University, Ithaca, NY 14850, USA
| | - Naomi E. Langmore
- Research School of Biology, Australian National University, Canberra, Australian Capital Territory 0200, Australia
| | - Michelle L. Hall
- School of BioSciences, University of Melbourne, Melbourne, Victoria 3010, Australia
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21
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Patricelli GL, Hebets EA, Mendelson TC. Book review of Prum, R. O. 2018. The evolution of beauty: How Darwin's forgotten theory of mate choice shapes the animal world-and us (2017), Doubleday, 428 pages, ISBN: 9780385537216. Evolution 2018. [DOI: 10.1111/evo.13629] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Affiliation(s)
- Gail L. Patricelli
- Department of Evolution and Ecology; University of California; Davis California 95616
| | - Eileen A. Hebets
- School of Biological Sciences; University of Nebraska-Lincoln; Lincoln Nebraska 68588
| | - Tamra C. Mendelson
- Department of Biological Sciences; University of Maryland Baltimore County; Baltimore Maryland 21250
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