Paco Calvo

Cognition in Plants

We discuss the possibility and the meaning of the claim that plants are cognitive from the perspective of embodied cognition. In embodied cognition, the notion of cognition can be interpreted in a very broad way and applied to many free-moving creatures. In this chapter, we discuss whether and (if so) how this approach applies to intelligence in plants. Building on work from “plant neurobiology,” we discuss the differences in speed between plants and animals, similarities between sensory-driven plant growth and animal memory, and the presence of offline behavior in plants. In our view, these examples show that under a wide, embodied interpretation of cognition, plants may well qualify as being cognitive.

Conditions for minimal intelligence across eukaryota: a cognitive science perspective.

What is minimal intelligence? Generally speaking, our understanding of intelligence has to do with sets of biological functions of organisms that exhibit a degree of flexibility against contingencies in their environment-induced behavioral repertoire. In principle, sensory perception, sensory-motor coordination, basic forms of learning and memory, decision-making and problem solving, are all marks of minimal intelligence subject to scrutiny with the toolkit of the cognitive sciences. The bottom line is that an appraisal of the behavioral repertoire of eukaryotes, and of the organizational features that sustain it, resists an interpretation in reactive, non-cognitive, terms.

“Feature Detection” vs. “Predictive Coding” Models of Plant Behavior

In this article we consider the possibility that plants exhibit anticipatory behavior, a mark of intelligence. If plants are able to anticipate and respond accordingly to varying states of their surroundings, as opposed to merely responding online to environmental contingencies, then such capacity may be in principle testable, and subject to empirical scrutiny. Our main thesis is that adaptive behavior can only take place by way of a mechanism that predicts the environmental sources of sensory stimulation. We propose to test for anticipation in plants experimentally by contrasting two empirical hypotheses: “feature detection” and “predictive coding.” We spell out what these contrasting hypotheses consist of by way of illustration from the animal literature, and consider how to transfer the rationale involved to the plant literature.

How Many Mechanisms Are Needed to Analyze Speech? A Connectionist Simulation of Structural Rule Learning in Artificial Language Acquisition

Some empirical evidence in the artificial language acquisition literature has been taken to suggest that statistical learning mechanisms are insufficient for extracting structural information from an artificial language. According to the more than one mechanism (MOM) hypothesis, at least two mechanisms are required in order to acquire language from speech: (a) a statistical mechanism for speech segmentation; and (b) an additional rule-following mechanism in order to induce grammatical regularities. In this article, we present a set of neural network studies demonstrating that a single statistical mechanism can mimic the apparent discovery of structural regularities, beyond the segmentation of speech. We argue that our results undermine one argument for the MOM hypothesis.

Predicting green: really radical (plant) predictive processing

In this article we account for the way plants respond to salient features of their environment under the free-energy principle for biological systems. Biological self-organization amounts to the minimization of surprise over time. We posit that any self-organizing system must embody a generative model whose predictions ensure that (expected) free energy is minimized through action. Plants respond in a fast, and yet coordinated manner, to environmental contingencies. They pro-actively sample their local environment to elicit information with an adaptive value. Our main thesis is that plant behaviour takes place by way of a process (active inference) that predicts the environmental sources of sensory stimulation. This principle, we argue, endows plants with a form of perception that underwrites purposeful, anticipatory behaviour. The aim of the article is to assess the prospects of a radical predictive processing story that would follow naturally from the free-energy principle for biological systems; an approach that may ultimately bear upon our understanding of life and cognition more broadly.

The philosophy of plant neurobiology: a manifesto

Abstract‘Plant neurobiology’ has emerged in recent years as a multidisciplinary endeavor carried out mainly by steady collaboration within the plant sciences. The field proposes a particular approach to the study of plant intelligence by putting forward an integrated view of plant signaling and adaptive behavior. Its objective is to account for the way plants perceive and act in a purposeful manner. But it is not only the plant sciences that constitute plant neurobiology. Resources from philosophy and cognitive science are central to such an interdisciplinary project, if plant neurobiology is to maintain its target well-focused. This manifesto outlines a road map for the establishment and development of a new subject—the Philosophy of Plant Neurobiology—, a new field of research emerging at the intersection of the philosophy of cognitive science and plant neurobiology. The discipline is herewith presented, introducing challenges and novel lines of engagement with the empirical investigation, and providing an explanatory framework and guiding principles that will hopefully ease the integration of research on the quest for plant intelligence.

ARE PLANTS SENTIENT

Feelings in humans are mental states representing groups of physiological functions that usually have defined behavioural purposes. Feelings, being evolutionarily ancient, are thought to be coordinated in the brain stem of animals. One function of the brain is to prioritise between competing mental states and, thus, groups of physiological functions and in turn behaviour. Plants use groups of coordinated physiological activities to deal with defined environmental situations but currently have no known mental state to prioritise any order of response. Plants do have a nervous system based on action potentials transmitted along phloem conduits but which in addition, through anastomoses and other cross-links, forms a complex network. The emergent potential for this excitable network to form a mental state is unknown, but it might be used to distinguish between different and even contradictory signals to the individual plant and thus determine a priority of response. This plant nervous system stretches throughout the whole plant providing the potential for assessment in all parts and commensurate with its self-organising, phenotypically plastic behaviour. Plasticity may, in turn, depend heavily on the instructive capabilities of local bioelectric fields enabling both a degree of behavioural independence but influenced by the condition of the whole plant.

General Issues in the Cognitive Analysis of Plant Learning and Intelligence

In this chapter, we identify issues related to the terms behavior, intelligence, and cognition. We also point out problems with inconsistencies in the definitions of learning phenomena and whether plant intelligence needs to be interpreted in cognitive terms. As an alternative to the cognitive model of plant intelligence, we encourage researchers to consider a model combining the radical behaviorism of B. F. Skinner with the ecological psychology of J. J. Gibson where the focus of both perspectives is on the functional analysis of behavior and the recognition of alternative paths to the emergence of intelligence over the course of natural history.

Guidance of circumnutation of climbing bean stems: An ecological exploration

In this report we explore the guidance of circumnutation of climbing bean stems under the light of general rho/tau theory, a theory that aims to explain how living organisms guide goal-directed movements ecologically. We present some preliminary results on the control of circumnutation by climbing beans, and explore the possibility that the power of movement in plants, more generally, is controlled under ecological principles.

Could Plants Be Sentient

Feelings in humans are mental states representing groups of physiological functions that usually have defined behavioural objectives or purpose. Feelings are thought to be coordinated in the brain stem of animals and are evolutionarily ancient. One function of the brain is to prioritise between competing mental states, and thus groups of physiological functions and in turn behaviour. Anger, fear or pain call for immediate action whereas hunger, or thirst, signify longer term needs and a requirement for search. Plants use groups of coordinated physiological activities to deal with defined environmental situations but currently have no known mental state to prioritise any order of response. Plants do have a nervous system based on phloem which is highly cross linked. Its potential for forming a mental state is unknown but it could be used to distinguish between different and even contradictory signals and thus determine a priority of response. The vascular nervous system stretches throughout the whole plant providing the potential for assessment in all parts and commensurate with its self-organising, phenotypically plastic behaviour.