« Back to Table of Content || Next »

Appendix 1. Glossary

Many definitions of mental processes came into Neuroscience from Psychology and Philosophy. They were introduced when scientists did not know about the neuronal structure and organization of the brain. As our understanding of the brain progresses, there is a clear need to redefine many mental processes from the neurological perspective. Such re-definitions will facilitate communication between scientists studying the mind and enhance the process of discovery. In this book, we defined a number of mental processes from the neurological perspective. New terms that were introduced in this book and, therefore, have not yet been vetted in a scientific process, are marked by asterisks.

*Attention rhythm

There is strong evidence that conscious perception is associated with the global synchronization of neuronal assemblies in the β-frequency (15-25 Hertz). Accordingly, we decided to refer to the β-frequency wave as an attention rhythm. Such a naming emphasizes that consciousness is not continuous in time but intermittent, with 15 to 25 frames per second. According to the theory put forth in this book, neuronal assemblies that intend to reach consciousness have to fire action potentials in synchrony with, and on the upswing of the attention rhythm. The assemblies firing out-of-phase or on the downswing of the attention rhythm cannot be registered by the consciousness. These assemblies continue processing information and serving their voting decisions subconsciously. Their work is not registered by the mind.

Consciousness

In this book, consciousness is used in its common sense connotation, meaning awareness.

Conscious experience

In this book, conscious experience is used in its common sense connotation, that is, any experience of which a subject is aware. A conscious experience includes many states ranging from passive awareness to active voluntary mental synthesis. A conscious experience also includes a number of special states such as hallucination and dreaming. Neurologically, a conscious experience can be defined simply as the synchronous firing of a neuronal ensemble in-phase and on the upswing of the attention wave. For example, when observing an ambiguous image such as Dalí’s Slave Market with the Disappearing Bust of Voltaire, the conscious experience flickers between perceiving the nuns and the bust of Voltaire. When the nuns are perceived, the neuronal ensemble representing the nuns is activated and synchronized with the attention wave. When the bust of Voltaire is perceived, the neuronal ensemble representing Voltaire is activated and synchronized with the attention wave.

Hippocampus

The hippocampus is a group of specialized neurons located deep inside the temporal lobe. The hippocampus is essential for forming long-term memories of people, places and events. Once formed, these memories reside in cerebral cortices. Long-term memories of people, places and events cannot form when the hippocampi are surgically removed from both hemispheres as was demonstrated in the seminal case of the patient “HM”.

Hominid

In this book, hominid is used to describe modern humans and their extinct relatives. The more scientifically correct term would be hominan: a member of the Hominina tribe.

*Mental image

A mental image is a visual image generated from memory. The easiest way to experience a mental image is to close your eyes and recall a picture. (When the eyes are open, we usually experience a visual percept; although sometimes we experience a mental image even when the eyes are open). Neurologically, experiencing a mental image of an object requires an activation of the neural ensemble that represents the object and synchronization of the ensemble with the attention rhythm.

*Mental synthesis

Mental synthesis is the process of synthesizing a new, never-before-seen mental image from two or more mental images. In a more general sense, mental synthesis is the process of creating any new imaginary experience in the mind by combining any number of previous experiences together. Neurologically, mental synthesis is the process of synchronizing two or more neuronal ensembles with the attention rhythm. For example , you can imagine your favorite cup standing on top of your favorite keyboard. Neurologically, the mental formation of the cup on top of the keyboard image consists of the following steps:

(1) Conscious frame 1: the neuronal ensemble representing the cup is activated and synchronized with the attention rhythm. The mental image of the cup is experienced.
(2) Conscious frame 2 (60 milliseconds later): the neuronal ensemble representing the keyboard is activated and synchronized with the attention rhythm. The mental image of the keyboard is experienced. 
(3) Conscious frame 3 (120 milliseconds later): the neuronal ensembles representing the cup and the keyboard are synchronized with the attention rhythm. The mental image of the cup standing on top of the keyboard is experienced. Neurons in the prefrontal cortex (frontal lobe, abbreviated FL) execute the synchronization.
(4) The connections between the activated neurons are strengthened and, thus, the new neuronal ensemble representing the cup on the keyboard is formed (black pyramid). This ensemble will be stored in memory and can be activated at a later time as one unit.

Another good example of mental synthesis is the process occurring in your mind when you wake up in the middle of night, trying to find a solution to a problem. With your eyes closed, you visualize all the possible scenarios and attempt to follow through each one of them to select an optimal solution.

The theory put forth in this book identifies voluntary mental synthesis as a uniquely human trait and describes the evolutionary forces that drove hominids towards the acquisition of mental synthesis.

*Mental template

A mental template is an image formed in the mind by means of a reduction of a larger image from memory or visual percept. The process of mental template formation is different from mental synthesis: while mental synthesis involves integration of two or more neuronal ensembles together into one synchronously firing unit, mental template formation entails deactivation and/or desynchronization of part of a neuronal ensemble in order to experience a smaller object. The neurological process of mental template formation is similar to that involved in visual analysis. The difference is that mental template formation is a voluntary process, while visual analysis is an automatic, involuntary process.

According to the theory put forth in this book, involuntary visual analysis developed in hominids first and was followed by the acquisition of voluntary visual analysis - the capability to form a mental template. The first species capable of forming a mental template was Homo habilis (2.4 to 1.6 million years ago). As a result, Homo habilis gained the ability to manufacture simple stone choppers. When looking at a natural cobble, the prefrontal cortex of the Homo habilis was able to identify the neuronal ensemble encoding a chopper (mental template for a chopper) and to shift other neurons in the visual cortex (encoding flakes) out-of-phase with the attention rhythm. Note that a complete cobble had already been registered by the hominid’s eyes and was represented in his visual cortex. When the hominid shifted the neurons encoding flakes out-of-phase with his attention rhythm, the parts of the visual cortex registering the flakes were de-synchronized, and therefore were no longer present in the hominid’s conscious experience. The neuronal ensemble encoding the chopper remained in-phase with the attention rhythm, which enabled the hominid to consciously experience the mental template of the chopper, that is, to “see” the chopper inside the cobble.

On the other hand, species of the Australopithecus genus (5 to 2.3 million years ago) had likely not yet acquired the ability to voluntarily shift neuronal ensembles out-of-phase with the attention rhythm in order to concentrate on one visual detail: they were not able to see a future chopper inside a cobble.

Mental template formation is a precursor to mental synthesis. While mental template formation involves shifting some neurons out-of-phase with the attention rhythm, mental synthesis involves shifting neurons (of several neuronal ensembles) in-phase with the attention rhythm.

*Non-synthesizing language

A non-synthesizing language is a language that is not intended for synthesis of new, never-before-seen images in the mind of the listener. In other words, a non-synthesizing language is not intended for communication that involves mental synthesis. As far as we can tell, animal language in the wild is non-synthesizing. It is not intended for synthesis of new, never-before-seen images in the mind of the listeners. Even animals that have been trained to use hundreds of words in a lab still do not learn mental synthesis. It is likely that animals lack the neuronal apparatus necessary for mental synthesis. Consequently, no degree of training could teach an animal to synthesize new mental images.

Archeological evidence indicates that the vocal apparatus consistently improved in hominids from Homo ergaster to Neanderthals. Taken together with genetic findings, this indicates that hominids needed to express a greater number of words. It is likely that Homo ergaster and Neanderthals used a complex (multi-word) non-synthesizing language.

*Synthesizing language

A synthesizing language is a complex language that is intended to synthesize new, never-before-seen images in the mind of the listener. A synthesizing language allows humans to share their conscious experiences (both real and imaginary) with other humans by synthesizing new mental images in the mind of the listener. A synthesizing language greatly benefits a community in which individuals are capable of mental synthesis. A synthesizing language was likely acquired by Homo sapiens shortly after acquisition of mental synthesis, some time before Homo sapiens spread out of Africa 50,000 years ago. Evolutionarily, the synthesizing language was likely preceded by a complex multi-word non-synthesizing language that slowly improved the morphology of the vocal apparatus and advanced the neurological organization of the linguistic cortex. This process enabled hominids to speak and recognize many words long before the acquisition of either mental synthesis or a synthesizing language.

*Visual analysis

Visual analysis is a visual identification method based on matching available visual details (an ear or a tail) directly to targets in memory, without the intermediate step of amodal completion. This method requires that the visual system had already disassembled a complete object into elements at some prior time and stored those elements in memory. To match an ear to a leopard, the representation of the ear must be stored in memory and be associated with a leopard. To match a tail to a leopard, the representation of the tail must be stored in memory and be associated with a leopard. Numerous small details such as eyes, ears, tails, palms, and spots on skin, have to be stored in memory. The analysis of a visual scene is then performed serially: the visual system extracts the first meaningful element from the visual field (an ear visible above the grass) and attempts to match it to memory. It then extracts a second meaningful element (a tail) and matches it to memory, and so on until the object is recognized. Note that analysis involves the disassembly of an object into meaningful parts as opposed to synthesis, which involves combining two or more objects together. In majority of right-handed modern humans, visual analysis is primarily a function of the left hemisphere.

Neurologically, visual analysis is associated with dissecting a visual image into a number of smallest meaningful neuronal ensembles. Each ensemble is then stored in memory for matching to a stimulus at a later time.

According to the theory put forth in this book, visual analysis was refined in australopithecines (5 to 2.3 million years ago) to benefit recognition of predators partially obstructed by tall grasses of savanna. Automatic visual analysis was a precursor to voluntary visual analysis (mental template formation), which  was acquired by Homo habilis (2.4 to 1.6 million years ago) and was later refined in Homo ergaster/erectus (2 million to 100,000 years ago).