What is the Source Monitoring Error? (A guide)

In this guide, we will explain what is Source Monitoring; Source Monitoring Error; and the types of memory and their significance.

The concept of Source Monitoring Error

The concept of Source Monitoring refers to “the set of processes involved in establishing the origin of memories, knowledge and beliefs.” In addition to reality monitoring, which consists of identifying the internal/external origin, Source Monitoring includes the precise identification of the external source (external monitoring), and the discrimination of what is said or acted, regarding what imagined or thought for itself (internal monitoring). 

The determination of the origin of the information is based on the attributes of the information, including the sensory richness of the events actually perceived, in relation to the imagined ones, the comparison with the stored characteristics of a specific source or the contextual information that is possessed. 

Although the above emphasizes the need for adequate memory functioning, in its coding and recovery aspects, a modular multiple-input memory (MEM) model has been proposed, according to which no mental operation or brain area specifically, it is responsible for the proper functioning of the source monitoring.

Most of the time, the origin of the information is decided in a “heuristic” way, based on the qualitative characteristics and in an automatic way, although it is also possible to resort to a “systematic”, slower analysis, which makes use of previously existing information. Both processes can be activated together and be influenced by biases, metacognitions and goals.

Source Monitoring Error

Since Source Monitoring depends on the previous information available, its operation is limited by the degree of sensory richness of the acquired memory and by the factors that regulate the acquisition, coding and contextualization of the initial event and the subject’s ability to remember it.

Neuroanatomical studies find evidence that lesions in the frontal and temporal lobes are associated with failures in Source Monitoring. In general, while the temporal medial lobe is in charge of encoding, contextual organization and storage of information, the prefrontal regions perform the functions of analysis, search and retrieval of it.

Typically, source monitoring is studied through tests in which the subject must decide if a word belongs to a previously presented list and/or if it was previously produced by himself or the examiner (reality monitoring). 

The ability to discriminate between imagined or seen items from others verbally expressed by the subject (internal monitoring) has also been investigated. It has been reported that various forms of dementia, in addition to normal ageing, occur with alterations in Source Monitoring.

In the case of people suffering from schizophrenia, in addition to a nuclear failure in the basic sense of belonging and self-identity, a deficit in monitoring mental activity has been reported, including difficulty in identifying mental acts as their own or others. 

In particular, it has been reported that patients with schizophrenia more frequently make errors of false recognition of words not previously presented, as well as of attribution to the examiner of their own items and of confusing mental acts with actions actually performed.

From a psychopathological point of view, it has been postulated that Source Monitoring Errors are associated with the presence of psychotic symptoms in people with schizophrenia and with schizotypy traits in the general population. Although much less studied, an inverse relationship between deficit symptoms and source monitoring errors has also been reported.

In relation to cognitive functioning, multiple regression analysis found that attention, working memory and sequential organization, together, predict performance on an Internal Monitoring test in people with schizophrenia. 

The types of memory and their significance

A type of unconscious memory has been defined as implicit memory that differs from explicit memory. This distinction was introduced by Graf and Schacter in 1985: 

“Implicit memory manifests itself when performing a task is facilitated without conscious recovery, while explicit memory manifests itself when performing a task requires conscious retrieval of previous experience.“

A fundamental distinction between memory types was the one proposed in 1968 by Atkinson and Shiffrin between short-term memory (MTS) and long-term memory (MTL).  The first refers to those elements that remain conscious for a short period of time and that are overlooked if strategies for “storage” in MTL are not implemented. 

Let’s think, for example, when someone gives us their phone number and we can’t write it down. When we get home it is very difficult to remember it if we have not tried to repeat it at least a few times. Instead, we have no problem remembering a number we dial every day because it is in our long-term memory. 

The capacity of MTS was measured and it was seen that most people are able to repeat a sequence of 7 digits, with a deviation of 2. Most people manage, therefore, to “store” in MTS from 5 to 9 items.

In 1972, Tulving proposed the first distinction within long-term memory between episodic memory and semantic memory, in which episodic memory refers to the system that stores specific information and events with their temporal location and depending on the identity of the subject, and through semantic memory of what general knowledge represents, their meanings, symbols and relationships. 

Consider, for example, a classic memorization experiment. Subjects are asked to read a list of 20 words and then asked to repeat them. It will probably be hard for them to remember all 20 words on the list. Suppose a person remembers the words “chair,” “glass,” “tree,” but forgets to say the word “pot.” 

The fact that the subject forgot to repeat the word “pot” does not mean that the subject does not know what a pot is or what it is used for. The concept of “pot” is well present in the semantic memory of the individual, but it is not present in episodic memory. Both types of memory are considered part of explicit knowledge.

Over time, studies of patients suffering from amnesia and brain trauma, as well as the introduction of concepts such as procedural memory, have led the authors to propose a theory of memory that takes into account all these new elements. Thus, in 1994, Tulving and Schacter proposed the theory of memory systems, in which 5 systems are considered:

Working memory: indicates short-term memory; working memory is, in fact, intended for the temporary storage of linguistic, visual and spatial information and for the maintenance of internal representations as a guide for future behaviour or as a basis for higher-level cognitive operations.

Episodic memory: allows the acquisition and retrieval of information on specific events located in time; allows the correct recording of experiences with accurate autobiographical reporting

Semantic memory: the characteristic knowledge of semantic memory, although of an episodic origin, has lost its temporal and spatial coordinates to become a heritage of general knowledge about the world of the subject

Procedural memory: Procedural memory aims to learn motor and cognitive skills (for example, cycling). The system is characterized by several subsystems that have in common the characteristic of allowing the acquisition of new skills.

It differs from the episodic system and the semantic system by the ability to work properly even in the presence of dysfunctions of these systems, not missing from the literature cases of amnesiacs who learned skills without remembering learning experiences. A notable feature is that during system-specific gradual learning, a gradual change in brain pathways is also observed.

Perception representation system, which allows the identification of shapes and structures without processing their meaning. Meaning is processed by semantic memory which, under normal conditions, works with this system without interruption, but in the case of brain damage, it highlights how individuals can recognize and identify objects, but without understanding their meaning.

Conclusions

In this guide, we explained what is Source Monitoring; Source Monitoring Error; and the types of memory and their significance.

Source Monitoring includes the precise identification of the external source (external monitoring), and the discrimination of what is said or acted, regarding what imagined or thought for itself (internal monitoring). 

Since Source Monitoring depends on the previous information available, its operation is limited by the degree of sensory richness of the acquired memory and by the factors that regulate the acquisition, coding and contextualization of the initial event and the subject’s ability to remember it.

From a psychopathological point of view, it has been postulated that Source Monitoring Errors are associated with the presence of psychotic symptoms in people with schizophrenia and with schizotypy traits in the general population.

If you have any comments or questions, please let us know!

Further reading

Intraub, H. (2010). Rethinking Scene Perception. Psychology of Learning and Motivation, 231–264. doi:10.1016/s0079-7421(10)52006-1

Lindsay, D. S. (2008). Source Monitoring. Learning and Memory: A Comprehensive Reference, 325–347. doi:10.1016/b978-012370509-9.00175-3 

Johnson, M. K. (2001). False Memories, Psychology of. International Encyclopedia of the Social & Behavioral Sciences, 5254–5259. doi:10.1016/b0-08-043076-7/01503-5 

Eich, E., Geraerts, E., Schooler, J. W., & Forgas, J. P. (2008). Memory in and about Affect. Learning and Memory: A Comprehensive Reference, 239–260. doi:10.1016/b978-012370509-9.00146-7 

References

Johnson M, Hashtroudi S, Lindsay S. Source Monitoring Psychological Bulletin 1993; 1: 3-28.

Johnson M. MEM: mechanism of recollection Journal of Cognitive neuroscience 1992; 4: 268-80.

Mitchell K, Johnson M Source monitoring 15 years later: What have we learned from fMRI about the neural mechanisms of source memory? Psychol Bull 2009; 135: 638-77.

Harvey P. Reality monitoring in mania and schizophrenia. The association of thought disorder and performance J Nerv Ment Dis 1985; 173: 67-73.

Humpston C, Linden D, Evans L. Deficits in reality and internal source monitoring of actions are associated with the positive dimension of schizotypy. Psychiatry Res 2017; 250: 44-9.

Garrison J, Moseley P, Alderson-Day B, Smailes D, Fernyhough C, Simons J. Testing continuum models of psychosis: No reduction in source monitoring ability in healthy individuals prone to auditory hallucinations. Cortex 2016;