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Ponkshe A, Blancas Barroso J, Abramson CI, Calvo P. A case study of learning in plants: Lessons learned from pea plants. Q J Exp Psychol (Hove) 2024; 77:1272-1280. [PMID: 37705453 DOI: 10.1177/17470218231203078] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 09/15/2023]
Abstract
To facilitate the study of learning in plants, we share our experiences of trying to replicate the pea plant experiment of Gagliano et al. In the course of our efforts, we identified 11 issues that must be addressed when attempting to replicate these experiments. The issues range from germination and transplantation of seedlings to experimental design and apparatus issues. We propose a number of solutions to overcome these hurdles.
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Affiliation(s)
- Aditya Ponkshe
- Minimal Intelligence Laboratory (MINTLab), Minimal Intelligence Laboratory, University of Murcia, Murcia, Spain
| | - Jacobo Blancas Barroso
- Minimal Intelligence Laboratory (MINTLab), Minimal Intelligence Laboratory, University of Murcia, Murcia, Spain
| | - Charles I Abramson
- Laboratory of Comparative Psychology and Behavioral Biology, Oklahoma State University, Stillwater, OK, USA
| | - Paco Calvo
- Minimal Intelligence Laboratory (MINTLab), Minimal Intelligence Laboratory, University of Murcia, Murcia, Spain
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Korres NE, Norsworthy JK, FitzSimons T, Roberts TL, Oosterhuis DM, Govindjee G. Evaluation of secondary sexual dimorphism of the dioecious Amaranthus palmeri under abiotic stress. Sci Rep 2023; 13:13156. [PMID: 37573387 PMCID: PMC10423251 DOI: 10.1038/s41598-023-40453-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2022] [Accepted: 08/10/2023] [Indexed: 08/14/2023] Open
Abstract
The evolution of secondary sex-specific traits of dioecious species under abiotic stress conditions has received limited research, especially in the case of Amaranthus palmeri, a fast adapting and highly competing plant. Here, we have examined the interactive effects of abiotic stress on mineral accumulation, chlorophyll a and b content, and the operating capacity of Photosystem II (PSII) in both male and female A. palmeri plants grown under three different intensities of white light, and under N, K or P deficiency. Mineral profiling of the leaves and stems (with inflorescence) highlighted intra- and intersexual differences in their accumulation pattern and mineral associations. Chlorophyll a and chlorophyll b were different between the male and the female plants, being slightly lower in the latter, at high light intensity towards maturity, or under K or P deficiency. Further, slight, although statistically significant differences were recorded in the chlorophyll a/b ratio, which was lower at the higher light intensity in the female, over that in the male, plants towards maturity. Chlorophyll fluorescence parameters, i.e., steady state and maximum fluorescence increased under high light intensity, whereas the PSII operating efficiency decreased in the female plants, indicating reduced PSII capacity. Sex-specific differences in A. palmeri showed a differential response to stressful conditions because of differences in their ontogeny and physiology, and possibly due to the cost of reproduction. We suggest that the breeding system of dioecious species has weaknesses that can be used for the ecological management of dioecious weeds without relying on the use of herbicides.
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Affiliation(s)
- Nicholas E Korres
- School of Agriculture, Department of Agriculture, University of Ioannina, Kostakii, 47100, Arta, Greece.
| | - Jason K Norsworthy
- Crop Soil and Environmental Sciences, University of Arkansas, Fayetteville, AR, 72704, USA
| | | | - Trenton L Roberts
- Crop Soil and Environmental Sciences, University of Arkansas, Fayetteville, AR, 72704, USA
| | - Derrick M Oosterhuis
- Crop Soil and Environmental Sciences, University of Arkansas, Fayetteville, AR, 72704, USA
| | - Govindjee Govindjee
- Plant Biology, Biochemistry and Biophysics, University of Illinois at Urbana-Champaign, Urbana, IL, 61801, USA
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Reyes-Jiménez D, Iglesias-Parro S, Abad MJF, Paredes-Olay C. Effects of pre-exposure and post-exposure of the context in habituation of the retraction response in earthworms (Lumbricidae). Behav Processes 2021; 193:104527. [PMID: 34601052 DOI: 10.1016/j.beproc.2021.104527] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2021] [Revised: 09/08/2021] [Accepted: 09/28/2021] [Indexed: 11/19/2022]
Abstract
The context specificity of habituation has been demonstrated in earthworms. After the habituation of the retraction response to a light, a recovery of the response was observed when subjects are re-habituated in a different context. Some theories assume that an association between the context and the unconditioned stimulus could underlie this result. A series of experiments were conducted in order to test this issue. We assessed the potential disruptive effects of post-exposure (extinction effect) and pre-exposure of the context (latent inhibition effect) on the establishment of a context-US association. A recovery of response during subsequent rehabituation test was expected. The results of Experiment 1 showed that the extinction was effective, the post-exposure of the context after habituation produced a recovery of the retraction response. This result was replicated in Experiment 2 where the post-exposure condition was compared with a pre-exposure one. However, the pre-exposure to the context did not result in a recovery of the response in the rehabituation test, but also produced a general decrement on the response during the habituation training, that it has been interpreted as decrement in context's salience. In summary, these results suggest the involvement of associative and nonassociative processes in habituation learning.
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Affiliation(s)
- David Reyes-Jiménez
- Department of Psychology, Universidad de Jaén, Paraje las Lagunillas s/n, 23071 Jaén, Spain.
| | - Sergio Iglesias-Parro
- Department of Psychology, Universidad de Jaén, Paraje las Lagunillas s/n, 23071 Jaén, Spain.
| | - María J F Abad
- Department of Psychology, Universidad de Jaén, Paraje las Lagunillas s/n, 23071 Jaén, Spain.
| | - Concepción Paredes-Olay
- Department of Psychology, Universidad de Jaén, Paraje las Lagunillas s/n, 23071 Jaén, Spain.
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Segundo-Ortin M, Calvo P. Consciousness and cognition in plants. WILEY INTERDISCIPLINARY REVIEWS. COGNITIVE SCIENCE 2021; 13:e1578. [PMID: 34558231 DOI: 10.1002/wcs.1578] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/28/2020] [Revised: 08/26/2021] [Accepted: 08/30/2021] [Indexed: 12/17/2022]
Abstract
Unlike animal behavior, behavior in plants is traditionally assumed to be completely determined either genetically or environmentally. Under this assumption, plants are usually considered to be noncognitive organisms. This view nonetheless clashes with a growing body of empirical research that shows that many sophisticated cognitive capabilities traditionally assumed to be exclusive to animals are exhibited by plants too. Yet, if plants can be considered cognitive, even in a minimal sense, can they also be considered conscious? Some authors defend that the quest for plant consciousness is worth pursuing, under the premise that sentience can play a role in facilitating plant's sophisticated behavior. The goal of this article is not to provide a positive argument for plant cognition and consciousness, but to invite a constructive, empirically informed debate about it. After reviewing the empirical literature concerning plant cognition, we introduce the reader to the emerging field of plant neurobiology. Research on plant electrical and chemical signaling can help shed light into the biological bases for plant sentience. To conclude, we shall present a series of approaches to scientifically investigate plant consciousness. In sum, we invite the reader to consider the idea that if consciousness boils down to some form of biological adaptation, we should not exclude a priori the possibility that plants have evolved their own phenomenal experience of the world. This article is categorized under: Cognitive Biology > Evolutionary Roots of Cognition Philosophy > Consciousness Neuroscience > Cognition.
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Affiliation(s)
- Miguel Segundo-Ortin
- Department of Philosophy and Religious Studies, Faculty of Humanities, Utrecht University, Utrecht, The Netherlands
| | - Paco Calvo
- Minimal Intelligence Laboratory, Universidad de Murcia, Murcia, Spain
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Mallatt J, Blatt MR, Draguhn A, Robinson DG, Taiz L. Debunking a myth: plant consciousness. PROTOPLASMA 2021; 258:459-476. [PMID: 33196907 PMCID: PMC8052213 DOI: 10.1007/s00709-020-01579-w] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/27/2020] [Accepted: 10/22/2020] [Indexed: 05/18/2023]
Abstract
Claims that plants have conscious experiences have increased in recent years and have received wide coverage, from the popular media to scientific journals. Such claims are misleading and have the potential to misdirect funding and governmental policy decisions. After defining basic, primary consciousness, we provide new arguments against 12 core claims made by the proponents of plant consciousness. Three important new conclusions of our study are (1) plants have not been shown to perform the proactive, anticipatory behaviors associated with consciousness, but only to sense and follow stimulus trails reactively; (2) electrophysiological signaling in plants serves immediate physiological functions rather than integrative-information processing as in nervous systems of animals, giving no indication of plant consciousness; (3) the controversial claim of classical Pavlovian learning in plants, even if correct, is irrelevant because this type of learning does not require consciousness. Finally, we present our own hypothesis, based on two logical assumptions, concerning which organisms possess consciousness. Our first assumption is that affective (emotional) consciousness is marked by an advanced capacity for operant learning about rewards and punishments. Our second assumption is that image-based conscious experience is marked by demonstrably mapped representations of the external environment within the body. Certain animals fit both of these criteria, but plants fit neither. We conclude that claims for plant consciousness are highly speculative and lack sound scientific support.
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Affiliation(s)
- Jon Mallatt
- The University of Washington WWAMI Medical Education Program at The University of Idaho, Moscow, ID 83844 USA
| | - Michael R. Blatt
- Laboratory of Plant Physiology and Biophysics, Bower Building, University of Glasgow, Glasgow, G12 8QQ UK
| | - Andreas Draguhn
- Institute for Physiology and Pathophysiology, Medical Faculty, University of Heidelberg, 69120 Heidelberg, Germany
| | - David G. Robinson
- Centre for Organismal Studies, University of Heidelberg, 69120 Heidelberg, Germany
| | - Lincoln Taiz
- Department of Molecular, Cellular, and Developmental Biology, University of California, Santa Cruz, CA 95064 USA
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Mallatt J, Blatt MR, Draguhn A, Robinson DG, Taiz L. Debunking a myth: plant consciousness. PROTOPLASMA 2021. [PMID: 33196907 DOI: 10.1007/s00709-026-01579-w] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 05/10/2023]
Abstract
Claims that plants have conscious experiences have increased in recent years and have received wide coverage, from the popular media to scientific journals. Such claims are misleading and have the potential to misdirect funding and governmental policy decisions. After defining basic, primary consciousness, we provide new arguments against 12 core claims made by the proponents of plant consciousness. Three important new conclusions of our study are (1) plants have not been shown to perform the proactive, anticipatory behaviors associated with consciousness, but only to sense and follow stimulus trails reactively; (2) electrophysiological signaling in plants serves immediate physiological functions rather than integrative-information processing as in nervous systems of animals, giving no indication of plant consciousness; (3) the controversial claim of classical Pavlovian learning in plants, even if correct, is irrelevant because this type of learning does not require consciousness. Finally, we present our own hypothesis, based on two logical assumptions, concerning which organisms possess consciousness. Our first assumption is that affective (emotional) consciousness is marked by an advanced capacity for operant learning about rewards and punishments. Our second assumption is that image-based conscious experience is marked by demonstrably mapped representations of the external environment within the body. Certain animals fit both of these criteria, but plants fit neither. We conclude that claims for plant consciousness are highly speculative and lack sound scientific support.
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Affiliation(s)
- Jon Mallatt
- The University of Washington WWAMI Medical Education Program at The University of Idaho, Moscow, ID, 83844, USA.
| | - Michael R Blatt
- Laboratory of Plant Physiology and Biophysics, Bower Building, University of Glasgow, Glasgow, G12 8QQ, UK
| | - Andreas Draguhn
- Institute for Physiology and Pathophysiology, Medical Faculty, University of Heidelberg, 69120, Heidelberg, Germany
| | - David G Robinson
- Centre for Organismal Studies, University of Heidelberg, 69120, Heidelberg, Germany
| | - Lincoln Taiz
- Department of Molecular, Cellular, and Developmental Biology, University of California, Santa Cruz, CA, 95064, USA
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Abstract
Gagliano et al. (Learning by association in plants, 2016) reported associative learning in pea plants. Associative learning has long been considered a behavior performed only by animals, making this claim particularly newsworthy and interesting. In the experiment, plants were trained in Y-shaped mazes for 3 days with fans and lights attached at the top of the maze. Training consisted of wind consistently preceding light from either the same or the opposite arm of the maze. When plant growth forced a decision between the two arms of the maze, fans alone were able to influence growth direction, whereas the growth direction of untrained plants was not affected by fans. However, a replication of their protocol failed to demonstrate the same result, calling for further verification and study before mainstream acceptance of this paradigm-shifting phenomenon. This replication attempt used a larger sample size and fully blinded analysis.
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Affiliation(s)
- Kasey Markel
- Plant Biology, University of California, DavisDavisUnited States
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Markel K. Pavlov’s pea plants? Not so fast. An attempted replication of Gagliano et al. (December 2016).. [PMID: 0 DOI: 10.1101/2020.04.05.026823] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/25/2023]
Abstract
AbstractGaglianoet al. (Learning by association in plants, 2016) reported associative learning in pea plants. Associative learning has long been considered a behavior performed only by animals, making this claim particularly newsworthy and interesting. In the experiment, plants were trained in Y-shaped mazes for three days with fans and lights attached at the top of the maze. Training consisted of wind consistently preceding light from either the same or the opposite arm of the maze. When plant growth forced a decision between the two arms of the maze, fans alone were able to influence growth direction, whereas the growth direction of untrained plants was not affected by fans. Importantly, some plants were trained to grow towards the fan and others to grow away, demonstrating the flexibility of associative learning. However, a replication of their protocol failed to demonstrate the same result, calling for further verification and study before mainstream acceptance of this paradigm-shifting phenomenon. This replication attempt used a larger sample size and fully blinded analysis.
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Hantula DA. Audaciously under the Dome: Behavior Science in Systems and Society. Perspect Behav Sci 2019; 42:689-694. [PMID: 31976454 PMCID: PMC6901635 DOI: 10.1007/s40614-019-00238-7] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022] Open
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