Source Monitoring: 15 years later
The Dream, Henri Rosseau, (1910) MoMA
Source Monitoring was first described as a framework for understanding how people attribute the source of mental experiences in 1993 (Johnson, Hastroudi & Lindsay, see also Johnson & Raye). The Source Monitoring Framework (SMF) has been used by many labs in the last 15 years to investigate how the subjective experience affects memory judgments. Features that make up complex event memories are derived either perceptually through the senses or via thought (e.g. imagined or inferred) including:
- Perceptual information (e.g. size, taste)
- Spatial details (e.g. left or right of an object)
- Temporal details (e.g time of day, season)
- Semantic information (e.g. gist, category membership, associated items)
- Emotional information (how we or others felt)
- Records of the cognitive operations engaged (imagining, logical inference, counterfactual consideration)
The output from these different modalities and processes combine to constitute an episodic memory (Johnson, 2006). In addition to information or details, the recollection of episodic memories often generate phenomenal experiences, such as emotions, mental images, smells or the 'sense of being there' etc...
The contrast between detail and phenomenality is loosely captured by Endel Tulving's (1985) 'remember-know' distinction. Participants can sometimes know details of a prior event without putting themselves in the past, so to speak--a phenomenon known as 'mental time travel' (Suddendorf & Corballis, 2007). There are a few models that try to establish how details and familiarity interact to influence a remember/know judgment of a particular mental experience.
A promising two-dimensional model positions memory details on the y-axis and familiarity on the x-axis (Rotello, Macmillan, Reeder, 2004). A person is supposed to judge a mental experience as 'remembering' when the difference between details and familiarity is minimized and as 'knowing' when the difference between details and familiarity is pronounced, e.g., I remember being a bridesmaid for my best friend because I can bring to mind many details of the event and a strong emotional conviction that I attended. However, I only know that I completed yr.12 chemistry because whilst my familiarity is very high, my ability to pick out details of the the experience is limited. Conversely, I only know the public transport system of Montreal because I can bring to mind details of the trains and buses, but cannot remember learning about them.
A consistent question in the SMF is precisely how people use detail and familiarity to judge a mental experience as a memory. What evidence do we draw on to judge a particular mental event as referring to an event x rather than an imagining x?
It seems that mental experiences are attributed to source categories according to assumptions about average differences in the features that characterize sources (e.g. more affective information for actually experienced events, more cognitive operations for imagined events...). It may be that we build up expectations for experiences over time and use those expectations to guide our judgments about them.
Johnson, M.K. (2006). Memory and reality. American Psychologist, 61, 760-771.
Johnson, M.K., Hastroudi, S., & Lindsay, D. S. (1993). Source Monitoring. Psychological Bulletin, 114, 3-28.
Johnson, M.K., Raye, C.L. (1981). Reality Monitoring. Psychological Review, 88, 67-85.
Rotello, C. M., Macmillan, N. A., & Reeder, J. A. (2004) Sum–difference theory of remembering and knowing: A two-dimensional signal detection model. Psychological Review, 111, 588–616.
Suddendorf, T., & Corballis, M. C. (2007). The evolution of foresight: What is mental time travel, and is it unique to humans? Behavioral and Brain Sciences, 30(3), 299-313
Tulving, E. (1985). Memory and consciousness.Canadian Psychologist, 26, 1–12