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

Procedural Memory


Procedural memory includes motor skills, cognitive skill learning, simple classical conditioning, priming, habituation, sensitization, perceptual after-effects and other cognitive operations improved by experience. (Squire; Memory and Brain, 164, 170)

Procedural memory makes use of emotional memory but not declarative memory.

For implicit memory, there is reasonably good agreement that parts of the striatum, the cerebellum, and the brain stem are all involved in implicit learning and memory (Baddeley,; Memory, 272)

As a motor skill is learned, the basal ganglia take over the role of automatically executing the learned strategy. When basal ganglia are damaged, the person must revert to a slower, less automatic, and less accurate cortical mechanism for motor behavior. (Afifi; Functional Neuroanatomy, 290)

Motor Skills

Carrying out a well practiced skill, such as driving a car, in a highly automatic way. (Squire & Kandel; Memory, 178)

Brain areas that are specifically activated during sequence learning include the sensorimotor cortex and two deep structures of the brain known to be involved in motor learning, the caudate nucleus and putamen (collectively known as the neostriatum). (Squire & Kandel; Memory, 177)

It is not known where the memory trace of a motor skill is ultimately stored. (Squire & Kandel; Memory, 178)

Areas of the brain involved in attention and awareness may be needed early in skill learning, and these areas may become less important as learning proceeds. (Squire & Kandel; Memory, 178)

Prefrontal cortex tends to be engaged in early learning, which also engages the parietal cortex, an area known to be important for visual attention. (Squire & Kandel; Memory, 178)

Cerebellum is important in earlier stages of motor skill learning. (Squire & Kandel; Memory, 178)

Cerebellum is necessary for coordinating the specific repertoire of movements that are needed for well-executed, the skilled motion and for organizing the timing of these movements. (Squire & Kandel; Memory, 178)

Prefrontal cortex, parietal cortex, and cerebellum are all engaged early and motor skill learning. (Squire & Kandel; Memory, 178)

After practice with the skill, the prefrontal cortex, parietal cortex, and cerebellum all showed less activity, and other structures, including the motor cortex and nearby supplementary motor cortex, become more engaged. (Squire & Kandel; Memory, 178)

PET scan research has shown that the location of memory in the brain changes when explicit memory becomes implicit. (Ratey; User's Guide to Brain, 201)

Motor cortex, supplementary motor cortex, and neostriatum and may be the structures that store the skill-based information and long-term memory that allow the smooth execution of skill movements. (Squire & Kandel; Memory, 178)

Link to — Fixed Action Patterns (FAPs)

Research Study — Synaptic Motor Traces in the Motor Cortex


Implicit and Associatively Learned Behaviors

The associative processes, sensory guidance, and prepotent  reflexive mechanisms are considered to be the province of.posterior association regions, including the hippocampal formation — regions of the cerebrum, which have been accorded a major role in a large fraction of implicit and associatively learned behaviors and are considered the storage sites for the facts, events, instructions, concepts, rules, and habits that are the products of  long-term conditioning and practice. (Goldman-Rakic; Circuit Model of Working Memory, 131)



Priming refers to an improvement in and the ability to detect or to identify words or objects after recent experience with them. (Squire & Kandel; Memory, 160)

Priming's key feature is that it is unconscious.  Its function is to improve the perception of recently encountered stimuli, but we need not be aware that the speed or efficiency of perception is improved. (Squire & Kandel; Memory, 160)

Priming can persist for an exceedingly long time even after a single experience. (Squire & Kandel; Memory, 160)

Priming is independent of the ability to consciously remember. (Squire & Kandel; Memory, 160)

Priming involves brain systems other than the medial temporal lobe system that is essential for declarative memory. (Squire & Kandel; Memory, 160)

Priming can be highly visual and occurs early in the visual processing pathways before the analysis of meaning. (Squire & Kandel; Memory, 162)

One simple way of thinking about priming is that for a period of time after a word or other perceptual object is presented, less neural activity is required to process that same word or object. (Squire & Kandel; Memory, 162)

Perceptual priming occurs in the posterior cortex. (Squire & Kandel; Memory, 164)

Sensory input makes contact with information in the posterior cortex within 100 ms after the stimulus is presented. The perceptual task might now be handled by a small ensemble a well-tuned neurons, and the result would be a net reduction in neural activity during priming. (Squire & Kandel; Memory, 164)

Neural changes occur within the priming pathways well before information reaches the memory system of the medial temporal lobe, which is essential for declarative memory. (Squire & Kandel; Memory, 164)

Neural changes that occur after the medial temporal lobe is reached can be thought of as changes that help to create conscious declarative memories. (Squire & Kandel; Memory, 164)


Perceptual learning

With practice, people can improve their ability to discriminate texture, direction of motion, line orientation, and many other simple visual attributes. (Squire & Kandel; Memory, 165)

A training period of perceptual learning changes the structure of the sensory apparatus in the cortex that first receives information from the outside world. (Squire & Kandel; Memory, 164)


Perceptual and Cognitive Skills

Perceptual and cognitive skills. (Squire & Kandel; Memory, 181)


Category Learning

Learning about categories. (Squire & Kandel; Memory, 183)



Three simple forms of learning -- habituation, sensitization, classical conditioning. (Eichenbaum; Neuroscience of Memory, 41)

Habituation is learning to recognize, and ignore as familiar, unimportant stimuli that are monotonously repetitive. (Squire & Kandel; Memory, 26)

All of us use habituation every day to help us learn not to attend or respond to irrelevant stimuli. (Eichenbaum; Neuroscience of Memory, 41)

Habituation is a very simple form of learning, but it has the lasting property that indicates it is indeed a form of long-term memory. (Eichenbaum; Neuroscience of Memory, 41)

Striatum is a key element in the pathway for sequence learning and other aspects of habit learning involving the acquisition of stereotyped and unconscious behavioral repertoires. [FAPs] (Eichenbaum; Neuroscience of Memory, 250)



Sensitization is the opposite of a habituation -- it involves an increase in reflex magnitude as a result of prior stimulation. (Eichenbaum; Neuroscience of Memory, 43)

As the result of sensitization, when we encounter a fearful stimulus, such as a loud noise, we become for some time more likely to startle, or startle more vigorously. (Eichenbaum; Neuroscience of Memory, 43)


Classical conditioning

Classical conditioning involves the acquisition of an association between the first, or conditioned stimulus, and the second, unconditioned stimulus. (Eichenbaum; Neuroscience of Memory, 46)

In Pavlov's dogs, the conditioned stimulus was a tone that did not initially elicit salivation.  The tone was sounded in multiple trials prior to giving the dogs food.  After several pairings, the tone came to elict the conditioned response of salivation. (Eichenbaum; Neuroscience of Memory, 46)



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