Implicit and Explicit Memory Basics
Long-term memory is divided into two categories: implicit memory and explicit memory. These two systems (Implicit and Explicit Memory) represent different levels of consciousness and use separate brain processes. Despite the obvious separation between the two, research shows that implicit memory may impact explicit memory.
Unconscious memories are referred to as implicit memory. They are often more emotional and perceptional, making them difficult to express and explain. Intentional memories have an impact on our present conduct without us consciously recalling them.
Types and Examples
- Examples of procedural memory are learning how to drive a vehicle, knit, play an instrument, or play a video game. They’re often linked to “muscle memory,” or the ability to do certain activities automatically.
- Priming is a complicated psychological phenomenon in which an individual’s response to one stimulus (such as a word, picture, or action) influences their response to a second stimulus. These impacts are frequently subtle and may be exploited to influence people’s behaviour!
- The so-called “Pavlov’s Dog” reaction is classical conditioning, in which the person learns through association. A neutral stimulus (a bell) was coupled with a significant stimulus in this scenario (food). The dogs eventually learnt to associate the bell with food.
Explicit memory refers to memories that we can remember and describe consciously. They may be separated into two types: personal experiences and facts and information.
Implicit memories are learned and remembered more quickly than explicit memories. Implicit memories may be formed with only a single stimulus, but explicit memories need repeated stimulation and response cycles. That’s why you can’t remember a complete page of a book after just reading it once!
Types and Examples
- Personal experiences, such as the capacity to remember past events, are examples of episodic memories.
- The remembrance of bits of knowledge, definitions, and ideas is known as semantic memory. For instance, recalling crucial events from the American Civil War or understanding how people digest food.
- Autobiographical recollections let us form a more comprehensive picture of our lives’ experiences. They are made up of episodic and semantic memories. For example, you may not recall your birth, but you are aware of the city in which you were born.
- We navigate the environment around us using spatial memory, which is why we can quickly find our way around familiar cities.
Work on Patient H.M.
Work on a neurological patient named H.M. provided a lot of our early knowledge of the variations between these two memory systems (his full name was later revealed to be Henry Molaison). More about his narrative may be found in the explicit memory article.
He suffered from amnesia as a result of a lobotomy that damaged sections of his brain. Because of the nature of his forgetfulness, scientists were able to learn more about how various memory systems operate and the brain structures responsible for their operation. He was the subject of over a thousand published research studies.
Researchers were first shocked that he could acquire new abilities requiring hand-eye coordination despite his capacity to build new long-term memories (such as events and knowledge) (specifically, a mirror drawing exercise). He picked things up fast and increased his talents, but he had no recall of practising in the days before.
This study has progressed with more investigation into people with varied memory deficits as a consequence of trauma or neurodegeneration. The hippocampus, for example, is often the brain region most severely impacted by lesions in Alzheimer’s disease patients. As a result, Alzheimer’s patients’ capacity to develop and remember explicit memories is restored.
Brain Structures Involved
Communication between the hippocampus, prefrontal cortex, and amygdala is assumed to be the primary controller of explicit memory. Implicit memory, on the other hand, includes the basal ganglia and the cerebellum.
The hippocampus is a brain structure located deep inside the temporal lobe. It is especially important for transferring information from short-term to long-term memory and for spatial awareness. The prefrontal cortex is required for long-term memory storage and retrieval, especially of facts and information. The amygdala is a tiny region located near the brain that is involved in emotional memory and learning.
The cerebellum is a structure at the base of the brain that receives and executes fine motor movement impulses from the brain, spinal cord, and sensory systems. The cerebellum is important in the coordination and accuracy of activities, but does not initiate them. As a consequence, as part of the implicit memory system, it is critical in procedural memories.
The basal ganglia are a pair of brain regions that are located deep inside the brain. It is involved in a variety of learning and memory processes, as well as emotion regulation and habit building. The basal ganglia are also involved in “action selection,” which is especially crucial for regulating and smoothing out sequences of motions.
Relationship Between Implicit and Explicit Memory
Both implicit and explicit memory act separately to form human behaviour, yet they work together to shape human behaviour. It’s still unknown if they cooperate (i.e., function together) or whether one memory system is dominant and competes with the other. Stress, persistent drug use, and ageing are considered to affect the link between implicit and explicit memory (and which one takes control of a specific activity). Recent data suggests that implicit memory (particularly, priming) has a strong and quantitative impact on explicit memory (specifically, fact recall).
- Dew, I. T. Z., & Cabeza, R. (2011). The porous boundaries between explicit and implicit memory: behavioral and neural evidence. Annals of the New York Academy of Sciences, 1224(1), 174–190. https://doi.org/10.1111/j.1749-6632.2010.05946.x
- Squire, L. R. (2009, January 15). The Legacy of Patient H.M. for Neuroscience. Neuron, Vol. 61, pp. 6–9. https://doi.org/10.1016/j.neuron.2008.12.023
- Squire, L. R., & Dede, A. J. O. (2015). Conscious and unconscious memory systems. Cold Spring Harbor Perspectives in Medicine, 5(1). https://doi.org/10.1101/cshperspect.a021667