Scientific Understanding of Consciousness
Consciousness as an Emergent Property of Thalamocortical Activity

Associative nature of Memory



 All Memory Is Associative

Memories are necessarily associative and never identical. (Edelman; Wider than the Sky, 53)

By the associative property of memory, neural assemblies aggregate via the laws of Gestalts into the sparse but widespread neural assemblies of the dynamic core of consciousness.

The operation of association involves the linkage of information with other information. (Anderson; Associative Networks, 102)

Throughout the cerebral cortex, association becomes the essence of sensation, perception, and memory. (Fuster; Cortex and Mind, 8)


Link to — Autoassociation Attractor Systems


Any two cells or systems of cells that are repeatedly active at the same time will tend to become "associated," so that activity in one facilitates activity in the other. (Hebb; Organization of Behavior, 70)

Retrieval is a progression from one or more cues to the target memory, via associative connections linking them together, through a process of spreading activation. (Baddeley,; Memory, 166)

The key ingredient in the cortical globalization process is the ability of the oscillatory mechanisms to recruit anatomically distant cortical neurons into temporal coalitions. (Buzsáki; Rhythms of the Brain, 185)

Association is the most natural form of neural network computation. (Anderson; Associative Networks, 102)

The ability of autoassociative systems to reconstruct missing or noisy parts of the learned patterns. (Anderson; Associative Networks, 105)

Neurons may be connected in a vast associational network, similar to a relational database. (Baars - Essential Sources in Scientific Consciousness 68; Crick & Koch; Consciousness and Neuroscience, 48)

The enormous associative capabilities of the dynamic core are ideal to link or hierarchically organize a series of preexisting unconscious routines into a particular sequence. Pianist deliberately links separate arpeggio passages. (Edelman; Universe of Consciousness, 187)

Marr (1971) proposed a theory for how the hippocampus could function as an associative memory. From this proposal have followed many extensions, usually focusing on the role of the CA3 recurrent collaterals. (Arbib - Handbook of Brain Theory; Burgess; Hippocampus Spatial Models, 469)

Associativity -- Induction of LTP (long-term potentiation)   is Influenced by  Activity at Other Synapses. (Andersen; Hippocampus Book, 355)

Only temporally overlapping pairing of two inputs produce associative LTP. (Arbib - Handbook of Brain Theory; Burgess; Brown; Hebbian Plasticity, 455)

The ability to form associations between events including where they occur and what is present is the fundamental property of episodic memory. (Rolls; Emotion Explained, 196)

Noise and spontaneous firing help to ensure that when a stimulus arrives, there are always some neurons  very close to threshold  that respond rapidly, and then communicate their firing to other neurons through the modified synaptic weights, so that an attractor process can take place very rapidly. (Rolls & Deco; Noisy Brain, 78)

Noise inherent in brain activity has a number of advantages by making the dynamics stochastic, which allows for many remarkable features of the brain, including creativity,    probabilistic decision making,    stochastic resonance, unpredictability, conflict resolution, symmetry breaking, allocation to discrete categories, and many of the important memory properties. (Rolls & Deco; Noisy Brain, 80)


Research study — Overlapping Memory Trace Linking, but Not Recalling, Individual Memories

Research study — Associative Memory and Cortical-Hippocampal Brain Networks

Link to — Dynamic Core triggers Associated Memories

Research study — Retrieval of Knowledge Enhances LearningNot only does retrieval produce learning, but a retrieval event may actually represent a more powerful learning activity than an encoding event.

Research study — Entorhinal–Hippocampal Ensemble Activity during Associative Learning


Pattern Association for Neural Network Computation

Association is the most natural form of neural network computation. Neural networks can be thought of as pattern associaters, which link an input pattern with the most appropriate output pattern. (Anderson; Associative Networks, 102)

For classical conditioning in the cerebellum, the US and CS information must have pathways that bring them together    for associative learning of the CR to occur. (Arbib - Handbook of Brain Theory; Burgess; Bartha; Cerebellum and Conditioning, 169)

Relational processing at encoding enables flexible access to information and situations  quite different from those of the original learning. (Andersen; Hippocampus Book, 662)

It is suggested that an autoassociation memory implemented by the CA3 neurons enables whole (spatial) scene or episodic memories to be formed. The autoassociation memory described here shows how the episodic memory could be stored in the hippocampus, and later retrieved from the hippocampus and thereby to the neocortex using backprojections. (Rolls; Memory, Attention, and Decision-Making, 41)

Individual memories are formed by the facilitation, or perhaps creation, of synaptic connections between neurons that represent different sensory or motor functions, if and when such features co-occur in the internal or external environment. The temporal coincidence or continuity of attributes, which determines synaptic associations, may be accompanied by spatial contiguity. (Fuster; Memory in Cerebral Cortex, 11)

The informational content of memory networks resides in the associative relationships among the neuronal elements. (Fuster; Memory in Cerebral Cortex, 11)

Associative learning is a building block of memory and priming.  This mechanism of memory is judged to be shared by neuronal networks at all levels. (Allan Hobson, Consciousness, 88)

Gestalt proponents claimed that elements of a pattern are grouped together that are most proximal spatially; most proximal temporally; most similar geometrically; part of the most continuous pattern; part of the most closed pattern; arranged in uniform density; evolving with common fate; most symmetric; exhibiting a common orientation; or optimizing an intuitive measure of "figural goodness" or pragnanz. (Arbib - Handbook of Brain Theory; Burgess; Zucker; Perceptual Grouping, 725)


Research Study — Hippocampus Association Memory for Decisions

Research Study — Thalamus in Fear and MemoryMemories are never completely precise but always partially generalized, which enables an animal to quickly and appropriately respond to novel stimuli that resemble a previous experience.


Autoassociative Network

Neocortex recalls patterns autoassociatively, which means it can recall a complete pattern when given only a partial one.   (Gazzaniga; Human, 367)

Individuals with posttraumatic stress disorder (PTSD) typically report experiencing intrusive recollections, nightmares, and distress with physiologic arousal in response to reminders of trauma. (Vogt; Cingulate Neurobiology, 454)

The three brain regions of primary interest in PTSD have been the amygdala, ACC, and hippocampus. (Vogt; Cingulate Neurobiology, 454)

An autoassociator is a self-correcting network that can recreate a previously stored pattern that most closely resembles the current input pattern, even if it is only a fragment of the stored version. (Buzsáki; Rhythms of the Brain, 289)

The main factors that determine the maximum number of memories that can be stored in an autoassociative network are the number of connections on each neuron devoted to the recurrent collaterals, and the sparseness of the representation. (Rolls; Memory, Attention, and Decision-Making, 568)



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