By following a cognitive science link I came upon an article about Robert Hecht-Nielsen.
The Hecht-Nielsen theory posits that all aspects of cognition ?€“ seeing, hearing, understanding, planning and so on ?€“ are carried out using a single type of knowledge (antecedent support) and a single information processing operation called ?€˜confabulation?€™ which is carried out between the brain?€™s cerebral cortex and thalamus. The scientist?€™s theory hypothesizes that confabulation is the only information processing operation used in cognition. The theory also explains the cognitive mechanism by which behaviors (thoughts and movements) are launched, moment by moment, throughout the day.
One of the meanings of confabulate is “to fill in gaps in one’s memory with fabrications that one believes to be facts.” So, how does “cogent confabulation” posited by Hecht-Nielsen differ from something perceived at times to be pathological?
Armin Schnider in an article entitled “Spontaneous Confabulation and the Adapatation of Thought to Ongoing Reality” (Nature Reviews Neuroscience 4, 662 -671 (2003); doi:10.1038/nrn1179) notes the following:
Preface
Confabulation ?€” the production of fictitious stories ?€” has puzzled clinicians for over a century. Recent studies have singled out spontaneous confabulations as a distinct disorder that is characterized by an inability to adapt thought and behaviour to ongoing reality, so that patients act according to presently inappropriate memories. Lesions that lead people to confabulate always involve anterior limbic structures. Studies on healthy subjects and on patients with lesions of this type indicate that the orbitofrontal cortex, through subcortical connections, suppresses presently irrelevant memories even before their content is consciously recognized. The studies indicate that the monitoring of ongoing reality in thought might be a capacity of the brain’s reward system. (My emphasis)
Summary
- * Broadly defined, confabulation is the production of fictitious stories. There are different forms of confabulation, which have been classified in different ways by several authors. This multiplicity has made it difficult to understand the neural basis of the different forms. This article deals with one specific type ?€” spontaneous confabulation.
- * Spontaneous confabulation is a profound derangement of thought in which the patients’ ongoing reality and planning are dominated by their past experiences and habits. So, confabulations are the patients’ honest view of their perceived reality, and therefore lead them to act in accordance with mistaken beliefs.
- * The mechanisms that underlie the production of these fictitious stories are not yet fully understood, largely because many studies have not distinguished between patients with different forms of confabulation. As a result, there are many descriptive ideas, but few with predictive value. Despite this, the consensus is that confabulation is best characterized as a memory disorder.
- * In the view presented here, confabulation stems from confusion between presently relevant and irrelevant memories. More specifically, confusion seems to result from failure to suppress activated but presently irrelevant memory traces ?€” the monitoring of ongoing reality.
- * Spontaneous confabulation is only observed in people with brain lesions. Although the extent of such lesions is variable, they tend always to involve the posterior orbitofrontal cortex, or the anterior limbic structures that are directly connected with it. Imaging studies have confirmed this conclusion, as these regions are activated by tasks on which confabulating patients fail.
- * The adaptation of thought and behaviour to ongoing reality that seems to be affected in confabulators is mediated by the anterior limbic system, and acts by suppressing activated memory traces that do not pertain to ongoing reality. This finding allows exploration of how suppression works in the healthy brain. Electroencephalographic studies indicate that, at the cortical level, suppression is an early process that precedes learning and recognition. So, by the time an item is recognized, its cortical representation might have already been adjusted according to whether it relates to ongoing reality.
- * Imaging studies have shown that, in addition to the anterior limbic system, different components of the basal ganglia are activated when healthy subjects perform a task that elicits confabulation in patients. This observation has led to the proposal that monitoring of ongoing reality in thought might be related to the brain’s reward system.
