False Memories – A Faulty Reconstruction

We tend to place too much trust our memory and firmly believe that everything happened exactly as we recall it, but false memories do exist. While the most intuitive examples are those resulting from specific psychiatric disorders, false memories can easily be created without any pathological trigger.

Memory is a faulty reconstruction of our mental experiences, susceptible to being influenced by our prior knowledge, beliefs, goals, mental state, emotions, and social context. Thus, what is retrieved from memory can be substantially different from what was initially encoded, and what was encoded can also differ from what really happened.

There are different types of human memory. Sensory memory is information acquired and retained by the senses, for example remembering what something looks like after just a glimpse. Short-term memory (or working memory) is the temporary storage and manipulation of a small amount of information which is being processed and is readily-available at any time, necessary for complex cognitive tasks such as language. Long-term memory is the storage of information over an indefinite period of time. Long-term memory can either be explicit (conscious) or implicit (unconscious). The latter, also known as procedural memory is our “know-how”; our memory of skills and how to do things. Explicit or declarative memory is our “know-what”; our memories that can be consciously recalled such as facts, knowledge or events.

Within declarative memory, we can differentiate semantic memory and episodic memory. Semantic memory is the registry of general facts, meanings, concepts and knowledge that is independent of personal experience and context. Episodic memory, on the other hand, is our recollection of experiences and autobiographical events to which we can associate a context, a time, a place, and emotions; it is a representation of reality that aggregates multiple inputs and a constructive process that is liable to error and bias. According to numerous behavioral and neuroimaging studies, it is the constructive nature of episodic memory that that lays the groundwork for the assembly of false memories.

Memory creation includes at least three different processes susceptible to specific errors that may result in false memories: encoding, consolidation and retrieval.

Encoding, the first step in memory formation, begins with perception through the senses and allows the perceived event to be converted into a construct that can be stored in the brain and accessed later. An example of false memories formed at encoding is seen when a memory of an imagined event is falsely remembered as a perceived event. It is likely that this is due to the similar characteristics of imagined and perceived events that are translated into similar encoding mechanisms.

Consolidation, the processes of memory stabilization after the encoding, is actively affected by sleep. Interestingly, recent studies have suggested that sleep may not only be essential for the accurate consolidation of declarative memory, but also promote declarative memory distortions. As a result, false memories can be created during consolidation as new knowledge representations, distinct from the original encoded event.

Retrieval is the “remembering” of stored events or information. False memory generation at retrieval is mostly influenced by the cues or tasks that induce it. A common example is confusing a stranger with an old acquaintance because something in the stranger triggers a recollection that makes people believe they are recognizing someone they have never actually met before.

Despite being mostly inoffensive, false memories may actually be quite harmful when, for example, in a legal context, a “clear” recollection by a witness is actually not so clear, leading to wrong judicial decisions.

Keep this in mind the next time you argue about something you “clearly remember”.


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Image via B Calkins / Shutterstock.

Sara Adaes, PhD

Sara Adaes, PhD, has been a researcher in neuroscience for over a decade. She studied biochemistry and did her first research studies in neuropharmacology. She has since been investigating the neurobiological mechanisms of pain at the Faculty of Medicine of the University of Porto, in Portugal. Follow her on Twitter @saradaes
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