Indirect tests of memory

[4] Implicit measures, especially latency-based ones, typically struggle to achieve a satisfactory level of internal consistency and test-retest reliability.

[3][6] The IAT is a procedure applied to a variety of research topics, including examinations of self-esteem, consumer studies, and human sexuality.

[3] Often, it is the IAT's ability to skirt socially desirable response biases that makes it an attractive method, and it is often used in lieu of, or alongside explicit self-report measures.

In one such study, participant's attitudes towards Apple Macintosh and Microsoft Windows computers were compared using both an explicit measure and an IAT.

[12] Additionally, the IAT has been found to be extremely effective at predicting the sexual orientation of gay and heterosexual men.

However, additional research seems to have addressed this concern as several studies have shown that IAT effects are not on account of familiarity.

[3] The first experimenters to use the lexical decision task (LDT) were Meyer and Schvaneveldt in 1971 who measured semantic decisions and showed that people are faster to respond to words when they have already been shown a prime that is semantically related, for example faster to confirm "nurse" as a word when it is preceded by "doctor" than when it is preceded by "butter".

"The stimuli were generated on a Stromberg Carlson SC4060 graphics system, photographed on 16-mm movie film and presented on a rear-projection screen by a Perceptual Development Laboratories' Mark III Perceptoscope.

This technique measures reaction time and accuracy and has been used to examine our understanding of word meanings and syntactic structures.

[18] The left hemisphere of the brain uses a phonological, non-lexical strategy that changes graphemes into phonemes to sound out strings of letters.

[18] In the standard LDT participants have to read the string of letters in front of them, decide if it is a word or not, and then make their response by pressing a key.

[24] This activation strengthens the internal organization of the schema, making the word more accessible because it will come to mind more readily when only some of its components are presented.

[25] Furthermore, patients under anesthesia who listened to the words before surgery did not show any implicit learning using the WSC task.

[25] However, patients under anesthesia who listened to the words during surgery showed implicit memory using the WSC task.

[25] Researchers have also been using WSC tasks to investigate the implicit impact of exposure to appearance and weight related images in the media.

[1] They used four different types of presentation for the studying of words to test and compare these implicit memory tasks.

In the learning phase of the AGL task, the experimental group is given a number of sentences created using the artificial grammar.

The control group is given a number of random strings made up of the same letters, but not following the rules of the artificial grammar.

In the test phase, both groups are told that each letter string was actually a sentence created using a complex set of grammatical rules.

This was thought to increase the amount of implicit learning, as more complex rules are harder to perceive and participants were not attempting to find them.

This was thought to increase the amount of explicit learning, as participants were consciously attempting to find rules that were easy to perceive.

The results showed a greater activity in the left superior occipital cortex and right fusiform gyrus for grammatical stimuli, and greater activity in the left angular gyrus during grammaticality judgments, as compared to a matched recognition control task.

[30] Reber's original AGL theory is rule-based; participants learn and apply the formal rules of the artificial grammar through viewing grammatical strings.

The results showed that participants acquired a large number of imperfect and limited rules, however, they do lead to consistently correct judgments of grammaticality and non-grammaticality.

[38] Words that are lower in frequency are more likely to be identified correctly in the WFC test because they are more distinct, which makes them easier to recall.

[40] An example of a WFC test is as follows: Participants are presented with a list of words including ASSASSIN, EMISSARY, MYSTERY, PENDULUM, and THEOREM, among others.

A distracter task is utilized to redirect the participant's attention; they are asked to sort paint chips into their respective colour categories (red, blue, green, etc.).

[42] Research on LOP has further supported the finding that priming effects last longer for WFC than that of other implicit memory tests.

[1][40] An interesting finding through the use of this test is that the first letter of a word is particularly important in participants' ability to correctly determine its identity.

In fact, when tests that measure implicit memory are administered to people who suffer from amnesia, they show tendencies of responding to stimuli in ways which correlate with information previously presented but not explicitly remembered.