Awareness and integrated information theory identify plant meristems as sites of conscious activity.

Plants, lacking a brain or nervous system, are typically assumed not to be conscious. However, the biological function of consciousness is to guide adaptive behavior based on information. All organisms are aware of their surroundings and modify behavior to survive; awareness requires assessment, which in plants occurs through molecular and electrical mechanisms rather than neural ones. The integrated information theory (IIT), a leading theory of consciousness, does not require brains or synapses. According to IIT, plant awareness involves two kinds of information: communicative extrinsic information from environmental perception, and integrated intrinsic information located in shoot and root meristems and possibly cambium.

Study at a glance

Abstract

Lacking an anatomical brain/nervous system, it is assumed plants are not conscious. The biological function of consciousness is an input to behaviour; it is adaptive (subject to selection) and based on information. Complex language makes human consciousness unique. Consciousness is equated to awareness. All organisms are aware of their surroundings, modifying their behaviour to improve survival. Awareness requires assessment too. The mechanisms of animal assessment are neural while molecular and electrical in plants. Awareness of plants being also consciousness may resolve controversy. The integrated information theory (IIT), a leading theory of consciousness, is also blind to brains, nerves and synapses. The integrated information theory indicates plant awareness involves information of two kinds: (1) communicative, extrinsic information as a result of the perception of environmental changes and (2) integrated intrinsic information located in the shoot and root meristems and possibly cambium. The combination of information constructs an information nexus in the meristems leading to assessment and behaviour. The interpretation of integrated information in meristems probably involves the complex networks built around [Ca2+]i that also enable plant learning, memory and intelligent activities. A mature plant contains a large number of conjoined, conscious or aware, meristems possibly unique in the living kingdom.