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Garrett KA, Alcalá-Briseño RI, Andersen KF, Brawner J, Choudhury RA, Delaquis E, Fayette J, Poudel R, Purves D, Rothschild J, Small IM, Thomas-Sharma S, Xing Y. Effective Altruism as an Ethical Lens on Research Priorities. Phytopathology 2020; 110:708-722. [PMID: 31821114 DOI: 10.1094/phyto-05-19-0168-rvw] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
Effective altruism is an ethical framework for identifying the greatest potential benefits from investments. Here, we apply effective altruism concepts to maximize research benefits through identification of priority stakeholders, pathosystems, and research questions and technologies. Priority stakeholders for research benefits may include smallholder farmers who have not yet attained the minimal standards set out by the United Nations Sustainable Development Goals; these farmers would often have the most to gain from better crop disease management, if their management problems are tractable. In wildlands, prioritization has been based on the risk of extirpating keystone species, protecting ecosystem services, and preserving wild resources of importance to vulnerable people. Pathosystems may be prioritized based on yield and quality loss, and also factors such as whether other researchers would be unlikely to replace the research efforts if efforts were withdrawn, such as in the case of orphan crops and orphan pathosystems. Research products that help build sustainable and resilient systems can be particularly beneficial. The "value of information" from research can be evaluated in epidemic networks and landscapes, to identify priority locations for both benefits to individuals and to constrain regional epidemics. As decision-making becomes more consolidated and more networked in digital agricultural systems, the range of ethical considerations expands. Low-likelihood but high-damage scenarios such as generalist doomsday pathogens may be research priorities because of the extreme potential cost. Regional microbiomes constitute a commons, and avoiding the "tragedy of the microbiome commons" may depend on shifting research products from "common pool goods" to "public goods" or other categories. We provide suggestions for how individual researchers and funders may make altruism-driven research more effective.[Formula: see text] Copyright © 2020 The Author(s). This is an open access article distributed under the CC BY 4.0 International license.
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Affiliation(s)
- K A Garrett
- Plant Pathology Department, University of Florida, Gainesville, FL, U.S.A
- Institute for Sustainable Food Systems, University of Florida, Gainesville, FL, U.S.A
- Emerging Pathogens Institute, University of Florida, Gainesville, FL, U.S.A
| | - R I Alcalá-Briseño
- Plant Pathology Department, University of Florida, Gainesville, FL, U.S.A
- Institute for Sustainable Food Systems, University of Florida, Gainesville, FL, U.S.A
- Emerging Pathogens Institute, University of Florida, Gainesville, FL, U.S.A
| | - K F Andersen
- Plant Pathology Department, University of Florida, Gainesville, FL, U.S.A
- Institute for Sustainable Food Systems, University of Florida, Gainesville, FL, U.S.A
- Emerging Pathogens Institute, University of Florida, Gainesville, FL, U.S.A
| | - J Brawner
- Plant Pathology Department, University of Florida, Gainesville, FL, U.S.A
| | - R A Choudhury
- Plant Pathology Department, University of Florida, Gainesville, FL, U.S.A
- Institute for Sustainable Food Systems, University of Florida, Gainesville, FL, U.S.A
- Emerging Pathogens Institute, University of Florida, Gainesville, FL, U.S.A
| | - E Delaquis
- International Center for Tropical Agriculture (CIAT), Vientiane, Lao People's Democratic Republic
| | - J Fayette
- Plant Pathology Department, University of Florida, Gainesville, FL, U.S.A
- Institute for Sustainable Food Systems, University of Florida, Gainesville, FL, U.S.A
- Emerging Pathogens Institute, University of Florida, Gainesville, FL, U.S.A
| | - R Poudel
- Genomics and Bioinformatics Research Unit, United States Department of Agriculture-Agricultural Research Service, Gainesville, FL, U.S.A
| | - D Purves
- Philosophy Department, University of Florida, Gainesville, FL, U.S.A
| | - J Rothschild
- Philosophy Department, University of Florida, Gainesville, FL, U.S.A
| | - I M Small
- Plant Pathology Department, University of Florida, Gainesville, FL, U.S.A
- North Florida Research & Education Center, University of Florida, Quincy, FL, U.S.A
| | - S Thomas-Sharma
- Department of Plant Pathology and Crop Physiology, Louisiana State University Agricultural Center, Baton Rouge, LA, U.S.A
| | - Y Xing
- Plant Pathology Department, University of Florida, Gainesville, FL, U.S.A
- Institute for Sustainable Food Systems, University of Florida, Gainesville, FL, U.S.A
- Emerging Pathogens Institute, University of Florida, Gainesville, FL, U.S.A
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Abstract
The fact that seeing with two eyes is universal among vertebrates raises a problem that has long challenged vision scientists: how do animals with overlapping visual fields combine non-identical right and left eye images to achieve fusion and the perception of depth that follows? Most theories address this problem in terms of matching corresponding images on the right and left retinas. Here we suggest an alternative theory of binocular vision based on anatomical correspondence that circumvents the correspondence problem and provides a rationale for ocular dominance.
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Affiliation(s)
- Cherlyn J Ng
- Neuroscience and Behavioral Disorders Program, Duke-NUS Graduate Medical School Singapore, Singapore, Singapore.,Flaum Eye Institute, University of Rochester, Rochester, NY, United States.,Center for Visual Science, University of Rochester, Rochester, NY, United States
| | - Dale Purves
- Neuroscience and Behavioral Disorders Program, Duke-NUS Graduate Medical School Singapore, Singapore, Singapore.,Duke Institute for Brain Sciences, Duke University, Durham, NC, United States
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3
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Melville CA, Johnson PCD, Smiley E, Simpson N, McConnachie A, Purves D, Osugo M, Cooper SA. Statistical modelling studies examining the dimensional structure of psychopathology experienced by adults with intellectual disabilities: Systematic review. Res Dev Disabil 2016; 53-54:1-10. [PMID: 26852278 DOI: 10.1016/j.ridd.2016.01.018] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/17/2015] [Revised: 12/22/2015] [Accepted: 01/25/2016] [Indexed: 06/05/2023]
Abstract
Diagnosing mental ill-health using categorical classification systems has limited validity for clinical practice and research. Dimensions of psychopathology have greater validity than categorical diagnoses in the general population, but dimensional models have not had a significant impact on our understanding of mental ill-health and problem behaviours experienced by adults with intellectual disabilities. This paper systematically reviews the methods and findings from intellectual disabilities studies that use statistical methods to identify dimensions of psychopathology from data collected using structured assessments of psychopathology. The PRISMA framework for systematic review was used to identify studies for inclusion. Study methods were compared to best-practice guidelines on the use of exploratory factor analysis. Data from the 20 studies included suggest that it is possible to use statistical methods to model dimensions of psychopathology experienced by adults with intellectual disabilities. However, none of the studies used methods recommended for the analysis of non-continuous psychopathology data and all 20 studies used statistical methods that produce unstable results that lack reliability. Statistical modelling is a promising methodology to improve our understanding of mental ill-health experienced by adults with intellectual disabilities but future studies should use robust statistical methods to build on the existing evidence base.
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Affiliation(s)
- C A Melville
- Institute of Health and Wellbeing, College of Medical Veterinary and Life Sciences, University of Glasgow, Gartnavel Royal Hospital, 1055 Great Western Road, Glasgow G12 0XH, United Kingdom.
| | - P C D Johnson
- Institute of Health and Wellbeing, College of Medical Veterinary and Life Sciences, University of Glasgow, Gartnavel Royal Hospital, 1055 Great Western Road, Glasgow G12 0XH, United Kingdom
| | - E Smiley
- Institute of Health and Wellbeing, College of Medical Veterinary and Life Sciences, University of Glasgow, Gartnavel Royal Hospital, 1055 Great Western Road, Glasgow G12 0XH, United Kingdom
| | - N Simpson
- Institute of Health and Wellbeing, College of Medical Veterinary and Life Sciences, University of Glasgow, Gartnavel Royal Hospital, 1055 Great Western Road, Glasgow G12 0XH, United Kingdom
| | - A McConnachie
- Institute of Health and Wellbeing, College of Medical Veterinary and Life Sciences, University of Glasgow, Gartnavel Royal Hospital, 1055 Great Western Road, Glasgow G12 0XH, United Kingdom
| | - D Purves
- Institute of Health and Wellbeing, College of Medical Veterinary and Life Sciences, University of Glasgow, Gartnavel Royal Hospital, 1055 Great Western Road, Glasgow G12 0XH, United Kingdom
| | - M Osugo
- Institute of Health and Wellbeing, College of Medical Veterinary and Life Sciences, University of Glasgow, Gartnavel Royal Hospital, 1055 Great Western Road, Glasgow G12 0XH, United Kingdom
| | - S-A Cooper
- Institute of Health and Wellbeing, College of Medical Veterinary and Life Sciences, University of Glasgow, Gartnavel Royal Hospital, 1055 Great Western Road, Glasgow G12 0XH, United Kingdom
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Purves D, Morgenstern Y, Wojtach WT. Perception and Reality: Why a Wholly Empirical Paradigm is Needed to Understand Vision. Front Syst Neurosci 2015; 9:156. [PMID: 26635546 PMCID: PMC4649043 DOI: 10.3389/fnsys.2015.00156] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2015] [Accepted: 10/29/2015] [Indexed: 11/13/2022] Open
Abstract
A central puzzle in vision science is how perceptions that are routinely at odds with physical measurements of real world properties can arise from neural responses that nonetheless lead to effective behaviors. Here we argue that the solution depends on: (1) rejecting the assumption that the goal of vision is to recover, however imperfectly, properties of the world; and (2) replacing it with a paradigm in which perceptions reflect biological utility based on past experience rather than objective features of the environment. Present evidence is consistent with the conclusion that conceiving vision in wholly empirical terms provides a plausible way to understand what we see and why.
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Affiliation(s)
- Dale Purves
- Duke Institute for Brain Sciences, Duke UniversityDurham, NC, USA
| | | | - William T. Wojtach
- Duke Institute for Brain Sciences, Duke UniversityDurham, NC, USA
- Duke-NUS Graduate Medical SchoolSingapore, Singapore
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Abstract
The basis of musical consonance has been debated for centuries without resolution. Three interpretations have been considered: (i) that consonance derives from the mathematical simplicity of small integer ratios; (ii) that consonance derives from the physical absence of interference between harmonic spectra; and (iii) that consonance derives from the advantages of recognizing biological vocalization and human vocalization in particular. Whereas the mathematical and physical explanations are at odds with the evidence that has now accumulated, biology provides a plausible explanation for this central issue in music and audition.
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Affiliation(s)
- Daniel L Bowling
- Department of Cognitive Biology, University of Vienna, 1090 Vienna, Austria;
| | - Dale Purves
- Duke Institute for Brain Sciences, Duke University, Durham, NC 27708
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Abstract
Based on electrophysiological and anatomical studies, a prevalent conception is that the visual system recovers features of the world from retinal images to generate perceptions and guide behavior. This paradigm, however, is unable to explain why visual perceptions differ from physical measurements, or how behavior could routinely succeed on this basis. An alternative is that vision does not recover features of the world, but assigns perceptual qualities empirically by associating frequently occurring stimulus patterns with useful responses on the basis of survival and reproductive success. The purpose of the present article is to briefly describe this strategy of vision and the evidence for it.
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Affiliation(s)
- Dale Purves
- Duke Institute for Brain Sciences, Duke University, Durham, NC, USA
- Neuroscience and Behavioral Disorders Program, Duke-NUS Graduate Medical School Singapore, Singapore, Singapore
- Department of Neurobiology, Duke University, Durham, NC, USA
- *Correspondence: Dale Purves, Duke Institute for Brain Sciences, Duke University, PO Box 90999, Room B256, LSRC Building, 450 Research Drive, Durham, NC 27708, USA,
| | - Yaniv Morgenstern
- Neuroscience and Behavioral Disorders Program, Duke-NUS Graduate Medical School Singapore, Singapore, Singapore
| | - William T. Wojtach
- Duke Institute for Brain Sciences, Duke University, Durham, NC, USA
- Neuroscience and Behavioral Disorders Program, Duke-NUS Graduate Medical School Singapore, Singapore, Singapore
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Morgenstern Y, Rukmini DV, Monson BB, Purves D. Properties of artificial neurons that report lightness based on accumulated experience with luminance. Front Comput Neurosci 2014; 8:134. [PMID: 25404912 PMCID: PMC4217489 DOI: 10.3389/fncom.2014.00134] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2013] [Accepted: 10/01/2014] [Indexed: 11/13/2022] Open
Abstract
The responses of visual neurons in experimental animals have been extensively characterized. To ask whether these responses are consistent with a wholly empirical concept of visual perception, we optimized simple neural networks that responded according to the cumulative frequency of occurrence of local luminance patterns in retinal images. Based on this estimation of accumulated experience, the neuron responses showed classical center-surround receptive fields, luminance gain control and contrast gain control, the key properties of early level visual neurons determined in animal experiments. These results imply that a major purpose of pre-cortical neuronal circuitry is to contend with the inherently uncertain significance of luminance values in natural stimuli.
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Affiliation(s)
- Yaniv Morgenstern
- Neuroscience and Behavioral Disorders Program, Duke-NUS Graduate Medical School Singapore, Singapore
| | - Dhara V Rukmini
- Neuroscience and Behavioral Disorders Program, Duke-NUS Graduate Medical School Singapore, Singapore
| | - Brian B Monson
- Neuroscience and Behavioral Disorders Program, Duke-NUS Graduate Medical School Singapore, Singapore
| | - Dale Purves
- Neuroscience and Behavioral Disorders Program, Duke-NUS Graduate Medical School Singapore, Singapore ; Department of Neurobiology, Duke University Medical Center Durham, NC, USA ; Duke Institute for Brain Sciences, Duke University Durham, NC, USA
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Tappin DM, Bauld L, Purves D, Boyd K, Sinclair L, MacAskill S, McKell J, Friel B, McConnachie A, Coleman T. Cessation in Pregnancy Incentives Trial (CPIT): A phase II trial in Scotland 2011-2013. Eur J Public Health 2014. [DOI: 10.1093/eurpub/cku163.071] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
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9
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Ng C, Morgenstern Y, Purves D. Ocular dominance and retinotopic correspondence enable patent stereopsis. J Vis 2014. [DOI: 10.1167/14.10.968] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
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Abstract
Understanding why spectra that are physically the same appear different in different contexts (color contrast), whereas spectra that are physically different appear similar (color constancy) presents a major challenge in vision research. Here, we show that the responses of biologically inspired neural networks evolved on the basis of accumulated experience with spectral stimuli automatically generate contrast and constancy. The results imply that these phenomena are signatures of a strategy that biological vision uses to circumvent the inverse optics problem as it pertains to light spectra, and that double-opponent neurons in early-level vision evolve to serve this purpose. This strategy provides a way of understanding the peculiar relationship between the objective world and subjective color experience, as well as rationalizing the relevant visual circuitry without invoking feature detection or image representation.
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Affiliation(s)
- Yaniv Morgenstern
- Neuroscience and Behavioral Disorders Program, Duke-National University of Singapore Graduate Medical School, Singapore 169857; and
| | - Mohammad Rostami
- Neuroscience and Behavioral Disorders Program, Duke-National University of Singapore Graduate Medical School, Singapore 169857; and
| | - Dale Purves
- Neuroscience and Behavioral Disorders Program, Duke-National University of Singapore Graduate Medical School, Singapore 169857; andDuke Institute for Brain Sciences, Duke University, Durham, NC 27708
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Abstract
Biological visual systems cannot measure the properties that define the physical world. Nonetheless, visually guided behaviors of humans and other animals are routinely successful. The purpose of this article is to consider how this feat is accomplished. Most concepts of vision propose, explicitly or implicitly, that visual behavior depends on recovering the sources of stimulus features either directly or by a process of statistical inference. Here we argue that, given the inability of the visual system to access the properties of the world, these conceptual frameworks cannot account for the behavioral success of biological vision. The alternative we present is that the visual system links the frequency of occurrence of biologically determined stimuli to useful perceptual and behavioral responses without recovering real-world properties. The evidence for this interpretation of vision is that the frequency of occurrence of stimulus patterns predicts many basic aspects of what we actually see. This strategy provides a different way of conceiving the relationship between objective reality and subjective experience, and offers a way to understand the operating principles of visual circuitry without invoking feature detection, representation, or probabilistic inference.
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Affiliation(s)
- Dale Purves
- Neuroscience and Behavioral Disorders Program, Duke-NUS Graduate Medical School, Republic of Singapore 169857
- Department of Neurobiology, Duke University Medical Center, Durham, NC 27710; and
- Duke Institute for Brain Sciences, Duke University, Durham, NC 27708
| | - Brian B. Monson
- Neuroscience and Behavioral Disorders Program, Duke-NUS Graduate Medical School, Republic of Singapore 169857
| | - Janani Sundararajan
- Neuroscience and Behavioral Disorders Program, Duke-NUS Graduate Medical School, Republic of Singapore 169857
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Ghouri N, Purves D, McConnachie A, Wilson J, Gill JMR, Sattar N. Lower cardiorespiratory fitness contributes to increased insulin resistance and fasting glycaemia in middle-aged South Asian compared with European men living in the UK. Diabetologia 2013; 56:2238-49. [PMID: 23811809 PMCID: PMC3764328 DOI: 10.1007/s00125-013-2969-y] [Citation(s) in RCA: 40] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/21/2012] [Accepted: 05/17/2013] [Indexed: 02/06/2023]
Abstract
AIMS/HYPOTHESIS This study aimed to determine the extent to which increased insulin resistance and fasting glycaemia in South Asian men, compared with white European men, living in the UK, was due to lower cardiorespiratory fitness (maximal oxygen uptake [VO(2max)]) and physical activity. METHODS One hundred South Asian and 100 age- and BMI-matched European men without diagnosed diabetes, aged 40-70 years, had fasted blood taken for measurement of glucose concentration, HOMA-estimated insulin resistance (HOMA(IR)), plus other risk factors, and underwent assessment of physical activity (using accelerometry), VO(2max), body size and composition, and demographic and other lifestyle factors. For 13 South Asian and one European man, HbA1c levels were >6.5% (>48 mmol/mol), indicating potential undiagnosed diabetes; these men were excluded from the analyses. Linear regression models were used to determine the extent to which body size and composition, fitness and physical activity variables explained differences in HOMA(IR) and fasting glucose between South Asian and European men. RESULTS HOMA(IR) and fasting glucose were 67% (p < 0.001) and 3% (p < 0.018) higher, respectively, in South Asians than Europeans. Lower VO(2max), lower physical activity and greater total adiposity in South Asians individually explained 68% (95% CI 45%, 91%), 29% (11%, 46%) and 52% (30%, 80%), respectively, and together explained 83% (50%, 119%) (all p < 0.001) of the ethnic difference in HOMA(IR). Lower VO(2max) and greater total adiposity, respectively, explained 61% (9%, 111%) and 39% (9%, 76%) (combined effect 63% [8%, 115%]; all p < 0.05) of the ethnic difference in fasting glucose. CONCLUSIONS/INTERPRETATION Lower cardiorespiratory fitness is a key factor associated with the excess insulin resistance and fasting glycaemia in middle-aged South Asian, compared with European, men living in the UK.
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Affiliation(s)
- N. Ghouri
- BHF Glasgow Cardiovascular Research Centre, Institute of Cardiovascular and Medical Sciences, College of Medical, Veterinary and Life Sciences, University of Glasgow, Glasgow, G12 8TA UK
| | - D. Purves
- Robertson Centre for Biostatistics, Institute of Health and Wellbeing, University of Glasgow, Glasgow, UK
| | - A. McConnachie
- Robertson Centre for Biostatistics, Institute of Health and Wellbeing, University of Glasgow, Glasgow, UK
| | - J. Wilson
- BHF Glasgow Cardiovascular Research Centre, Institute of Cardiovascular and Medical Sciences, College of Medical, Veterinary and Life Sciences, University of Glasgow, Glasgow, G12 8TA UK
| | - J. M. R. Gill
- BHF Glasgow Cardiovascular Research Centre, Institute of Cardiovascular and Medical Sciences, College of Medical, Veterinary and Life Sciences, University of Glasgow, Glasgow, G12 8TA UK
| | - N. Sattar
- BHF Glasgow Cardiovascular Research Centre, Institute of Cardiovascular and Medical Sciences, College of Medical, Veterinary and Life Sciences, University of Glasgow, Glasgow, G12 8TA UK
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Ng C, Sundararajan J, Hogan M, Purves D. NETWORK CONNECTIONS THAT EVOLVE TO CONTEND WITH THE INVERSE OPTICS PROBLEM. J Vis 2013. [DOI: 10.1167/13.9.1158] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
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14
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Morgenstern Y, Rukmini DV, Purves D. Early level receptive field properties emerge from artificial neurons evolved on the basis of accumulated visual experience with natural images. J Vis 2013. [DOI: 10.1167/13.9.1160] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
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15
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Abstract
Audition--what listeners hear--is generally studied in terms of the physical properties of sound stimuli and physiological properties of the auditory system. Based on recent work in vision, we here consider an alternative perspective that sensory percepts are based on past experience. In this framework, basic auditory qualities (e.g., loudness and pitch) are based on the frequency of occurrence of stimulus patterns in natural acoustic stimuli. To explore this concept of audition, we examined five well-documented psychophysical functions. The frequency of occurrence of acoustic patterns in a database of natural sound stimuli (speech) predicts some qualitative aspects of these functions, but with substantial quantitative discrepancies. This approach may offer a rationale for auditory phenomena that are difficult to explain in terms of the physical attributes of the stimuli as such.
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Affiliation(s)
- Brian B Monson
- Neuroscience and Behavioral Disorders Program, Duke-NUS Graduate Medical School, Singapore.
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16
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Abstract
A fundamental problem in vision science is how useful perceptions and behaviors arise in the absence of information about the physical sources of retinal stimuli (the inverse optics problem). Psychophysical studies show that human observers contend with this problem by using the frequency of occurrence of stimulus patterns in cumulative experience to generate percepts. To begin to understand the neural mechanisms underlying this strategy, we examined the connectivity of simple neural networks evolved to respond according to the cumulative rank of stimulus luminance values. Evolved similarities with the connectivity of early level visual neurons suggests that biological visual circuitry uses the same mechanisms as a means of creating useful perceptions and behaviors without information about the real world.
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Affiliation(s)
- Cherlyn Ng
- Neuroscience and Behavioral Disorders Program, Duke-NUS Graduate Medical School Singapore, Singapore, Singapore
| | - Janani Sundararajan
- Neuroscience and Behavioral Disorders Program, Duke-NUS Graduate Medical School Singapore, Singapore, Singapore
| | - Michael Hogan
- Neuroscience and Behavioral Disorders Program, Duke-NUS Graduate Medical School Singapore, Singapore, Singapore
| | - Dale Purves
- Neuroscience and Behavioral Disorders Program, Duke-NUS Graduate Medical School Singapore, Singapore, Singapore
- Department of Neurobiology, Duke University Medical Center, Durham, North Carolina, United States of America
- Center for Cognitive Neuroscience, Duke University, Durham, North Carolina, United States of America
- * E-mail:
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17
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Allely C, Purves D, McConnachie A, Marwick H, Johnson P, Doolin O, Puckering C, Golding J, Gillberg C, Wilson P. Parent-infant vocalisations at 12 months predict psychopathology at 7 years. Res Dev Disabil 2013; 34:985-93. [PMID: 23291516 PMCID: PMC4046631 DOI: 10.1016/j.ridd.2012.11.024] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 09/29/2012] [Revised: 11/22/2012] [Accepted: 11/26/2012] [Indexed: 06/01/2023]
Abstract
This study investigated the utility of adult and infant vocalisation in the prediction of child psychopathology. Families were sampled from the Avon Longitudinal Study of Parents and Children (ALSPAC) birth cohort. Vocalisation patterns were obtained from 180 videos (60 cases and 120 randomly selected sex-matched controls) of parent-infant interactions when infants were one year old. Cases were infants who had been subsequently diagnosed aged seven years, with at least one psychiatric diagnostic categorisation using the Development and Wellbeing Assessment. Psychopathologies included in the case group were disruptive behaviour disorders, oppositional-conduct disorders, Attention Deficit Hyperactivity Disorder, pervasive development disorder, and emotional disorders. Associations between infant and parent vocalisations and later psychiatric diagnoses were investigated. Low frequencies of maternal vocalisation predicted later development of infant psychopathology. A reduction of five vocalisations per minute predicted a 44% (95%CI: 11-94%; p-value=0.006) increase in the odds of an infant being a case. No association was observed between infant vocalisations and overall case status. In sum, altered vocalisation frequency in mother-infant interactions at one year is a potential risk marker for later diagnosis of a range of child psychopathologies.
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Affiliation(s)
- C.S. Allely
- Institute of Health and Wellbeing, University of Glasgow, RHSC Yorkhill, Glasgow G3 8SJ, Scotland, United Kingdom
| | - D. Purves
- Robertson Centre for Biostatistics, Boyd Orr Building, University of Glasgow, Glasgow G12 8QQ, Scotland, United Kingdom
| | - A. McConnachie
- Robertson Centre for Biostatistics, Boyd Orr Building, University of Glasgow, Glasgow G12 8QQ, Scotland, United Kingdom
| | - H. Marwick
- National Centre for Autism Studies at the University of Strathclyde, Glasgow, Scotland, United Kingdom
| | - P. Johnson
- Robertson Centre for Biostatistics, Boyd Orr Building, University of Glasgow, Glasgow G12 8QQ, Scotland, United Kingdom
| | - O. Doolin
- Robertson Centre for Biostatistics, Boyd Orr Building, University of Glasgow, Glasgow G12 8QQ, Scotland, United Kingdom
| | - C. Puckering
- Institute of Health and Wellbeing, University of Glasgow, RHSC Yorkhill, Glasgow G3 8SJ, Scotland, United Kingdom
| | - J. Golding
- Centre for Child and Adolescent Health, School of Social and Community Medicine, University of Bristol, England, United Kingdom
| | - C. Gillberg
- Institute of Health and Wellbeing, University of Glasgow, RHSC Yorkhill, Glasgow G3 8SJ, Scotland, United Kingdom
| | - P. Wilson
- Centre for Rural Health, University of Aberdeen, The Centre for Health Science, Old Perth Road, Inverness IV2 3JH, Scotland, United Kingdom
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18
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Abstract
In Western music, the major mode is typically used to convey excited, happy, bright or martial emotions, whereas the minor mode typically conveys subdued, sad or dark emotions. Recent studies indicate that the differences between these modes parallel differences between the prosodic and spectral characteristics of voiced speech sounds uttered in corresponding emotional states. Here we ask whether tonality and emotion are similarly linked in an Eastern musical tradition. The results show that the tonal relationships used to express positive/excited and negative/subdued emotions in classical South Indian music are much the same as those used in Western music. Moreover, tonal variations in the prosody of English and Tamil speech uttered in different emotional states are parallel to the tonal trends in music. These results are consistent with the hypothesis that the association between musical tonality and emotion is based on universal vocal characteristics of different affective states.
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Affiliation(s)
- Daniel Liu Bowling
- Neuroscience and Behavioral Disorders Program, Duke-National University of Singapore, Graduate Medical School Singapore, Singapore, Singapore. dan.bowling.duke.edu
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19
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Abstract
This article considers visual perception, the nature of the information on which perceptions seem to be based, and the implications of a wholly empirical concept of perception and sensory processing for vision science. Evidence from studies of lightness, brightness, color, form, and motion all indicate that, because the visual system cannot access the physical world by means of retinal light patterns as such, what we see cannot and does not represent the actual properties of objects or images. The phenomenology of visual perceptions can be explained, however, in terms of empirical associations that link images whose meanings are inherently undetermined to their behavioral significance. Vision in these terms requires fundamentally different concepts of what we see, why, and how the visual system operates.
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Affiliation(s)
- Dale Purves
- Center for Cognitive Neuroscience, Department of Neurobiology, Duke University, Duke-National University of Singapore Graduate Medical School, Singapore 169857.
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Han SE, Sundararajan J, Bowling DL, Lake J, Purves D. Co-variation of tonality in the music and speech of different cultures. PLoS One 2011; 6:e20160. [PMID: 21637716 PMCID: PMC3103533 DOI: 10.1371/journal.pone.0020160] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2011] [Accepted: 04/13/2011] [Indexed: 12/01/2022] Open
Abstract
Whereas the use of discrete pitch intervals is characteristic of most musical traditions, the size of the intervals and the way in which they are used is culturally specific. Here we examine the hypothesis that these differences arise because of a link between the tonal characteristics of a culture's music and its speech. We tested this idea by comparing pitch intervals in the traditional music of three tone language cultures (Chinese, Thai and Vietnamese) and three non-tone language cultures (American, French and German) with pitch intervals between voiced speech segments. Changes in pitch direction occur more frequently and pitch intervals are larger in the music of tone compared to non-tone language cultures. More frequent changes in pitch direction and larger pitch intervals are also apparent in the speech of tone compared to non-tone language cultures. These observations suggest that the different tonal preferences apparent in music across cultures are closely related to the differences in the tonal characteristics of voiced speech.
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Affiliation(s)
- Shui' er Han
- Neuroscience and Behavioral Disorders Program, A*STAR Neuroscience Research Partnership, Duke-NUS Graduate Medical School, Singapore, Singapore,
| | - Janani Sundararajan
- Neuroscience and Behavioral Disorders Program, A*STAR Neuroscience Research Partnership, Duke-NUS Graduate Medical School, Singapore, Singapore,
| | - Daniel Liu Bowling
- Neuroscience and Behavioral Disorders Program, A*STAR Neuroscience Research Partnership, Duke-NUS Graduate Medical School, Singapore, Singapore,
- Department of Neurobiology, Duke University Medical Center, Durham, North Carolina, United States of America,
- Center for Cognitive Neuroscience, Levine Science Research Center, Duke University, Durham, North Carolina, United States of America,
| | - Jessica Lake
- Center for Cognitive Neuroscience, Levine Science Research Center, Duke University, Durham, North Carolina, United States of America,
- Department of Psychology and Neuroscience, Duke University, Durham, North Carolina, United States of America
| | - Dale Purves
- Neuroscience and Behavioral Disorders Program, A*STAR Neuroscience Research Partnership, Duke-NUS Graduate Medical School, Singapore, Singapore,
- Department of Neurobiology, Duke University Medical Center, Durham, North Carolina, United States of America,
- Center for Cognitive Neuroscience, Levine Science Research Center, Duke University, Durham, North Carolina, United States of America,
- Department of Psychology and Neuroscience, Duke University, Durham, North Carolina, United States of America
- * E-mail:
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Wojtach WT, Sung K, Purves D. Is motion perception completely determined by experience with moving objects? J Vis 2010. [DOI: 10.1167/6.6.1052] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
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22
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Purves D, Boots B. Evolution of visually guided behavior in artificial agents. J Vis 2010. [DOI: 10.1167/6.6.356] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
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Purves D, Howe CQ, Schwartz DA. Vision and the perception of music have a common denominator. J Vis 2010. [DOI: 10.1167/3.9.518] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
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24
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Howe CQ, Purves D. Size contrast explained by the statistics of scene geometry. J Vis 2010. [DOI: 10.1167/3.9.522] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
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25
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Yang Z, Purves D. The neural code for luminance. J Vis 2010. [DOI: 10.1167/5.8.670] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
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26
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Yang Z, Purves D. Statistical concatenations of luminance can explain lightness/brightness percepts. J Vis 2010. [DOI: 10.1167/3.9.423] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
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Long F, Purves D. Evidence that color contrast effects have a probabilistic foundation. J Vis 2010. [DOI: 10.1167/3.9.314] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
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28
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Purves D, Yang Z. The Poggendorff illusion explained by the statistics of natural scene geometry. J Vis 2010. [DOI: 10.1167/2.7.201] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
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29
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Yang Z, Purves D. Perception of objects that are both rotating and translating. J Vis 2010. [DOI: 10.1167/1.3.325] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
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Yang Z, Purves D. The probabilistic foundation of visual space. J Vis 2010. [DOI: 10.1167/2.7.715] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
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32
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Lotto RB, Purves D. An empirical explanation of the Chubb Illusion. J Vis 2010. [DOI: 10.1167/1.3.48] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
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33
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Long F, Purves D. A probabilistic explanation of simultaneous brightness contrast. J Vis 2010. [DOI: 10.1167/2.7.366] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
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34
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Purves D, Lotto B. Explanation of some major features of color perception. J Vis 2010. [DOI: 10.1167/1.3.60] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
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35
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Nundy S, Shimpi A, Purves D. The relationship between luminance and brightness. J Vis 2010. [DOI: 10.1167/1.3.426] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
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36
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Abstract
The affective impact of music arises from a variety of factors, including intensity, tempo, rhythm, and tonal relationships. The emotional coloring evoked by intensity, tempo, and rhythm appears to arise from association with the characteristics of human behavior in the corresponding condition; however, how and why particular tonal relationships in music convey distinct emotional effects are not clear. The hypothesis examined here is that major and minor tone collections elicit different affective reactions because their spectra are similar to the spectra of voiced speech uttered in different emotional states. To evaluate this possibility the spectra of the intervals that distinguish major and minor music were compared to the spectra of voiced segments in excited and subdued speech using fundamental frequency and frequency ratios as measures. Consistent with the hypothesis, the spectra of major intervals are more similar to spectra found in excited speech, whereas the spectra of particular minor intervals are more similar to the spectra of subdued speech. These results suggest that the characteristic affective impact of major and minor tone collections arises from associations routinely made between particular musical intervals and voiced speech.
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Affiliation(s)
- Daniel L Bowling
- Department of Neurobiology and Center for Cognitive Neuroscience, Duke University Durham, North Carolina 27708, USA
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Abstract
Scales are collections of tones that divide octaves into specific intervals used to create music. Since humans can distinguish about 240 different pitches over an octave in the mid-range of hearing, in principle a very large number of tone combinations could have been used for this purpose. Nonetheless, compositions in Western classical, folk and popular music as well as in many other musical traditions are based on a relatively small number of scales that typically comprise only five to seven tones. Why humans employ only a few of the enormous number of possible tone combinations to create music is not known. Here we show that the component intervals of the most widely used scales throughout history and across cultures are those with the greatest overall spectral similarity to a harmonic series. These findings suggest that humans prefer tone combinations that reflect the spectral characteristics of conspecific vocalizations. The analysis also highlights the spectral similarity among the scales used by different cultures.
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Affiliation(s)
- Kamraan Z. Gill
- Center for Cognitive Neuroscience and Department of Neurobiology, Duke University, Durham, North Carolina, United States of America
| | - Dale Purves
- Center for Cognitive Neuroscience and Department of Neurobiology, Duke University, Durham, North Carolina, United States of America
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Abstract
When a flash of light is presented in physical alignment with a moving object, the flash is perceived to lag behind the position of the object. This phenomenon, known as the flash-lag effect, has been of particular interest to vision scientists because of the challenge it presents to understanding how the visual system generates perceptions of objects in motion. Although various explanations have been offered, the significance of this effect remains a matter of debate. Here, we show that: (i) contrary to previous reports based on limited data, the flash-lag effect is an increasing nonlinear function of image speed; and (ii) this function is accurately predicted by the frequency of occurrence of image speeds generated by the perspective transformation of moving objects. These results support the conclusion that perceptions of the relative position of a moving object are determined by accumulated experience with image speeds, in this way allowing for visual behavior in response to real-world sources whose speeds and positions cannot be perceived directly.
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Affiliation(s)
- William T. Wojtach
- *Center for Cognitive Neuroscience, Box 90999, Duke University, Durham, NC 27708
| | - Kyongje Sung
- *Center for Cognitive Neuroscience, Box 90999, Duke University, Durham, NC 27708
| | - Sandra Truong
- *Center for Cognitive Neuroscience, Box 90999, Duke University, Durham, NC 27708
| | - Dale Purves
- Department of Neurobiology
- *Center for Cognitive Neuroscience, Box 90999, Duke University, Durham, NC 27708
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Purves D, Johnson DA, Hume RI. Regulation of synaptic connections in the rabbit ciliary ganglion. Ciba Found Symp 2008; 83:232-51. [PMID: 6913486 DOI: 10.1002/9780470720653.ch12] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
Abstract
One of the intriguing questions about the establishment of synaptic connections is how appropriate numbers of different axons come to innervate each target neuron. A reorganization of connections in early postnatal life appears to be an important aspect of this process, since many of the axons terminals that initially innervate target cells are subsequently lost. The rabbit ciliary ganglion is a remarkably simple neural ensemble in which to examine this rearrangement of developing synaptic connections. Using this system we have found that a reduction in the number of axons innervating each cell occurs without any change in the number of ciliary ganglion cells or preganglionic neurons; therefore the rearrangement is not based on cell death. The number of different axons that ultimately innervate each cell is, however, influenced in some way by the geometry of individual target neurons. Thus, mature ganglion cells that lack dendrites are generally innervated by a single axon, while neurons with increasingly complex dendritic arbors receive innervation from a commensurate number of different axons. At birth, on the other hand, neurons with or without dendritic processes receive about the same number of preganglionic inputs. These results suggest that the geometry of the target cell influences the competitive interaction between different axons innervating the same neuron. Indeed, an important function of dendrites may be to regulate the number of axons that innervate each nerve cell.
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Abstract
Throughout history and across cultures, humans have created music using pitch intervals that divide octaves into the 12 tones of the chromatic scale. Why these specific intervals in music are preferred, however, is not known. In the present study, we analyzed a database of individually spoken English vowel phones to examine the hypothesis that musical intervals arise from the relationships of the formants in speech spectra that determine the perceptions of distinct vowels. Expressed as ratios, the frequency relationships of the first two formants in vowel phones represent all 12 intervals of the chromatic scale. Were the formants to fall outside the ranges found in the human voice, their relationships would generate either a less complete or a more dilute representation of these specific intervals. These results imply that human preference for the intervals of the chromatic scale arises from experience with the way speech formants modulate laryngeal harmonics to create different phonemes.
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Affiliation(s)
- Deborah Ross
- Center for Cognitive Neuroscience and Department of Neurobiology, Duke University, Durham, NC 27708
| | - Jonathan Choi
- Center for Cognitive Neuroscience and Department of Neurobiology, Duke University, Durham, NC 27708
| | - Dale Purves
- Center for Cognitive Neuroscience and Department of Neurobiology, Duke University, Durham, NC 27708
- *To whom correspondence should be addressed. E-mail:
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43
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Abstract
Recent work on brightness, color, and form has suggested that human visual percepts represent the probable sources of retinal images rather than stimulus features as such. Here we investigate the plausibility of this empirical concept of vision by allowing autonomous agents to evolve in virtual environments based solely on the relative success of their behavior. The responses of evolved agents to visual stimuli indicate that fitness improves as the neural network control systems gradually incorporate the statistical relationship between projected images and behavior appropriate to the sources of the inherently ambiguous images. These results: (1) demonstrate the merits of a wholly empirical strategy of animal vision as a means of contending with the inverse optics problem; (2) argue that the information incorporated into biological visual processing circuitry is the relationship between images and their probable sources; and (3) suggest why human percepts do not map neatly onto physical reality.
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Affiliation(s)
- Byron Boots
- Department of Neurobiology and Center for Cognitive Neuroscience, Duke University, Durham, NC 27708, USA
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44
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Howe CQ, Beau Lotto R, Purves D. Comparison of Bayesian and empirical ranking approaches to visual perception. J Theor Biol 2006; 241:866-75. [PMID: 16537082 DOI: 10.1016/j.jtbi.2006.01.017] [Citation(s) in RCA: 33] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2005] [Revised: 01/12/2006] [Accepted: 01/18/2006] [Indexed: 11/21/2022]
Abstract
Much current vision research is predicated on the idea--and a rapidly growing body of evidence--that visual percepts are generated according to the empirical significance of light stimuli rather than their physical characteristics. As a result, an increasing number of investigators have asked how visual perception can be rationalized in these terms. Here, we compare two different theoretical frameworks for predicting what observers actually see in response to visual stimuli: Bayesian decision theory and empirical ranking theory. Deciding which of these approaches has greater merit is likely to determine how the statistical operations that apparently underlie visual perception are eventually understood.
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Affiliation(s)
- Catherine Q Howe
- Center for Cognitive Neuroscience and Department of Neurobiology, Duke University, Durham NC 27708, USA
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45
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Abstract
The perceptual color qualities of hue, saturation, and brightness do not correspond in any simple way to the physical characteristics of retinal stimuli, a fact that poses a major obstacle for any explanation of color vision. Here we test the hypothesis that these basic color attributes are determined by the statistical covariations in the spectral stimuli that humans have always experienced in typical visual environments. Using a database of 1,600 natural images, we analyzed the joint probability distributions of the physical variables most relevant to each of these perceptual qualities. The cumulative density functions derived from these distributions predict the major colorimetric functions that have been reported in psychophysical experiments over the last century.
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Affiliation(s)
- Fuhui Long
- Department of Neurobiology and Center for Cognitive Neuroscience, Duke University, Durham, NC 27708
| | - Zhiyong Yang
- Department of Neurobiology and Center for Cognitive Neuroscience, Duke University, Durham, NC 27708
| | - Dale Purves
- Department of Neurobiology and Center for Cognitive Neuroscience, Duke University, Durham, NC 27708
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Abstract
The fact that a perceptual experience akin to the familiar wagon-wheel illusion in movies and on TV can occur in the absence of stroboscopic presentation is intriguing because of its relevance to visuo-temporal parsing. The wagon-wheel effect in continuous light has also been the source of considerable misunderstanding and dispute, as is apparent in a series of recent papers. Here we review this potentially confusing evidence and suggest how it should be interpreted.
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Affiliation(s)
- Tim Andrews
- Department of Psychology, University of York, York, YO10 5DD, UK.
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48
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Purves D, Yang Z. Statistical basis for the perception of contrast, orientation, spatial frequency and color. J Vis 2005. [DOI: 10.1167/5.8.977] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
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49
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Abstract
The phenomenology of pitch has been difficult to rationalize and remains the subject of much debate. Here we test the hypothesis that audition generates pitch percepts by relating inherently ambiguous sound stimuli to their probable sources in the human auditory environment. A database of speech sounds, the principal source of periodic sound energy for human listeners, was compiled and the dominant periodicity of each speech sound determined. A set of synthetic test stimuli were used to assess whether the major pitch phenomena described in the literature could be explained by the probabilistic relationship between the stimuli and their probable sources (i.e., speech sounds). The phenomena tested included the perception of the missing fundamental, the pitch-shift of the residue, spectral dominance and the perception of pitch strength. In each case, the conditional probability distribution of speech sound periodicities accurately predicted the pitches normally heard in response to the test stimuli. We conclude from these findings that pitch entails an auditory process that relates inevitably ambiguous sound stimuli to their probable natural sources.
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Affiliation(s)
- David A Schwartz
- Center for Cognitive Neuroscience and Department of Neurobiology, Duke University, Box 90999, Durham, NC 27708-0999, USA.
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50
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Abstract
One of the most intriguing of the many discrepancies between perceived spatial relationships and the physical structure of visual stimuli is the Poggendorff illusion, when an obliquely oriented line that is interrupted no longer appears collinear. Although many different theories have been proposed to explain this effect, there has been no consensus about its cause. Here, we use a database of range images (i.e., images that include the distance from the image plane of every pixel in the scene) to show that the probability distribution of the possible locations of line segments across an interval in natural environments can fully account for all of the behavior of this otherwise puzzling phenomenon.
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Affiliation(s)
- Catherine Q Howe
- Center for Cognitive Neuroscience and Department of Neurobiology, Duke University, Durham, NC 27708, USA
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