Hierarchical Brain

An explanation of the human brain

First published 1st February 2024. This is version 1.5 published 2nd March 2024.
Three pages are not yet published: sleep, memory and an index.
Copyright © 2024 Email info@hierarchicalbrain.com

Warning - the conclusions of this website may be disturbing for some people without a stable mental disposition or with a religious conviction.

Thought and imagination

Thought and imagination, including planning, day-dreaming and night-time dreaming, all describe the same flow of activation between symbol schemas in my brain.

This concept is at the highest level in my seven-level hierarchical model because it depends on the existence of symbol schemas and the model of my world in my brain, and also on attention and consciousness. In fact, it is more than a dependency: the flow of my thoughts comes about simply because of the architecture of my model of the world and the process of attention, which is why a lot of the detail on this page is little more than a higher-level summary of the processing of lower levels.

Contents of this page
Overview - a high level description of thought.
Details - details of my proposals.
References - references and footnotes.


Details of my proposals

References For information on references, see structure of this website - references

  1. ^ Mental Models: Towards a Cognitive Science of Language, Inference, and Consciousness - Philip Johnson-Laird Cambridge University Press 1983
    see GoogleScholar.
    Page x (part of prologue), end of second paragraph to beginning of third: “...human beings construct mental models of their world... This idea is not new. Many years ago Kenneth Craik (1943) proposed that thinking is the manipulation of internal representations of the world.” (See reference 3 below.)
  2. ^ Ibid. Mental Models: Towards a Cognitive Science of Language, Inference, and Consciousness
    Page ix Prologue first paragraph: “Why is it that we cannot think everything at once but are forced to have one thought after another? Our memories exist together, yet we cannot call them to mind all at once, but only one at a time.”
  3. ^ The Nature of Explanation - Kenneth Craik Cambridge University Press 1943
    see GoogleScholar.
    Craik does not use the exact words that Johnson-Laird attributes to him in reference 1 above, but Chapter 5 entitled “Hypothesis on the nature of thought ” does have several statements that imply the same conclusion, although he is mainly describing prediction or planning rather than thoughts in general. See also The Nature of Explanation (a review).
    Page 51, first paragraph: “...this process of reasoning has produced a final result similar to that which might have been reached by causing the actual physical processes to occur.”
    Page 51, second paragraph, to page 52: “By a model we thus mean any physical or chemical system, which has a similar relation-structure to that of the process it imitates. By 'relation-structure' I do not mean some obscure non-physical entity which attends the model, but the fact that it is a physical working model which works in the same way as the process it parallels, in the aspects under consideration at any moment. Thus, the model need not resemble the real object pictorially; Kelvin’s tide predictor, which consists of a number of pulleys on levers, does not resemble a tide in appearance, but it works in the same way in certain essential respects - it combines oscillations of various frequencies so as to produce an oscillation which closely resembles in amplitude at each moment the variation in tide level at any place.”
    Page 57, fifth paragraph: “My hypothesis then is that thought models, or parallels, reality - that its essential feature is not 'the mind', 'the self', 'sense-data' nor propositions but symbolism, and that this symbolism is largely of the same kind as that which is familiar to us in mechanical devices which aid thought and calculation.”
    Page 60, second paragraph: “...our nervous systems do contain conducting sensory and motor paths and synapses in which there occurs states of excitation and volley of impulses which parallel the stimuli which occasioned them.”
    Page 61, second line: “If the organism carries a 'small-scale model' of external reality and of its own possible actions within its head, it is able to try out various alternatives, conclude which is the best of them, react to future situations before they arise, utilise the knowledge of past events in dealing with the present and future, and in every way to react in a much fuller, safer, and more competent manner to the emergencies which face it. Most of the greatest advances of modern technology have been instruments which extended the scope of our sense-organs, our brains or our limbs. Such are telescopes and microscopes, wireless, calculating machines, typewriters, motor cars, ships and aeroplanes. Is it not possible, therefore, that our brains themselves utilise comparable mechanisms to achieve the same ends and that these mechanisms can parallel phenomena in the external world as a calculating machine can parallel the development of strains in a bridge?”
    Pages 120-121, the concluding paragraph of the book: “..I have outlined a symbolic theory of thought, in which the nervous system is viewed as a calculating machine capable of modelling of paralleling external events, and have suggested that this process of paralleling is the basic feature of thought and explanation.”
  4. ^ Free agents: how evolution gave us free will - Mitchell 2023, Princeton University Press.
    Also see Free agents (Google books)
    Pages 137, fourth paragraph, in Chapter 6 entitled “Choosing” in the section headed “Simulating possible futures”: “First, some action plans are conceived of in the cortex. Doing so may entail the activation of different set of neurons, with each specific pattern corresponding to a particular action plan. At this point, these patterns represent the idea of doing something, not a commitment to it.” The text goes on to describe the convoluted mechanism involving the area of the brain called the basal ganglia, which can (indirectly) cause inhibition of the motor areas of the brain via neuromodulation, and then also how other neuromodulators can play a part in promoting some plans over others, depending on the priorities of the thing needed to be done.
  5. ^ Subjective signal strength distinguishes reality from imagination - Dijkstra and Fleming 2023
    doi: 10.1038/s41467-023-37322-1 downloadable here or see GoogleScholar.
    Beginning of discussion on page 6: “In this study we investigated how imagined and perceived signals interact to determine reality judgements. By combining large-scale single-trial psychophysics, computational modelling and neuroimaging, we find evidence in support of a theoretical model in which reality and imagination are intermixed to determine a unified sensory experience. This model runs counter to accounts in which imagery and perception are separable, and to earlier findings of the Perky effect which imply imagery suppresses perception of reality. When deciding whether an experience reflects external reality or internal imagination, our model compares the strength of this experience to a reality threshold. But if reality and imagination are subjectively intermixed by default, why do we not confuse them more often in daily life? We suggest that such confusions are rare simply because imagery is typically less vivid than veridical perception, rarely crossing the reality threshold. However, these results also suggest that if imagery does become vivid or strong enough, it will be indistinguishable from perception.”

Page last uploaded Thu Feb 22 04:39:39 2024 MST