Implicit memory

In psychology, implicit memory is one of the two main types of long-term human memory. It is acquired and used unconsciously, and can affect thoughts and behaviours. One of its most common forms is procedural memory, which allows people to perform certain tasks without conscious awareness of these previous experiences; for example, remembering how to tie one's shoes or ride a bicycle without consciously thinking about those activities. The type of knowledge that is stored in implicit memory is called implicit knowledge, implicit memory's counterpart is known as explicit memory or declarative memory, which refers to the conscious, intentional recollection of factual information, previous experiences and concepts. Evidence for implicit memory arises in priming, a process whereby subjects are measured by how they have improved their performance on tasks for which they have been subconsciously prepared. Implicit memory also leads to the illusory truth effect, which suggests that subjects are more likely to rate as true those statements that they have already heard, regardless of their truthfulness. Advanced studies of implicit memory began only in the 1980s. In early research, subjects were presented with words under different conditions and were given two types of tests: recognition memory tests and perceptual identification tests. These studies provided evidence that effects of memory on perceptual identification was independent of recognition memory. Jacoby & Brooks argued that perceptual identity effects reflect very rapid, context-specific learning. Unconscious influences of memory were found to alter the subjective experiences of participants. In one such study, participants judged that the white background noise was lower when they read words they had already been presented, thus misattributing their ease of perceiving the word to less noisy environment. This provided evidence for specific and long-living influences of past memory even when participants were unaware of its influence.