implicit memory which is also known as non-declarative memory

is a type of long term memory. Implicit memory influences behaviour but doesn’t involve conscious recollection. The three areas of implicit memory are; perceptual representation system, which is known as priming, procedural memory or ” skill learning” and classical conditioning.

Repetition priming is important because stimulus processing occurs quicker and it is more eligible on the second successive presentation of a stimuli. There are two types of priming, perceptual and conceptual. Perceptual priming indicates a repeated presentation of a stimulus which facilitates perceptual processing of it whilst conceptual priming shows there is facilitated processing of stimulus meaning.

Word recognition tests ( Tulving, Schacter and Stark 1982) involved giving subjects a word stem, for example TAB_ _ (TABLE) or a word fragment A_ _A_ _IN (ASSASSIN). Priming would be highlighted when an enhanced tendency to complete the test stems or fragments. Repetition priming studies target material which is presented in consciousness at the time whilst the test is being conducted. For example the subject may have completed a test fragment with a previously studied item.

Other situation targets content may have not been represented in consciousness at the time of the test. However it influences performances indirectly which indicates a contrast here. (Graff,Squire and Mandler 1984) had studied perceptual priming effects. Word lists were presented to subjects which involved three letter word fragments such as STR (STRAP). Subjects simply wrote the first word that came to them, STRAP or STRIP. Priming was assessed by the extent to which the word completion task corresponded to words from the list.

(Warrington and Weiskrantz 1974) conducted two implicit memory tasks. The implicit memory tasks involved amnesic patients and group participants whom were near enough identical. They found a double dissociation and no effect on the variable when measured by implicit tests.

Amnesic patients were used in a study conducted by Cermak et al (1985). They wanted to compare the performance of amnesic patients and non amnesic patients on perceptual priming. The task which was used involved was perceptual identification, which showed the presentation of words with less exposure time needed to determine them. Performance of the amnesic patients were similar to those of the control participants. The identification times were faster for the words which were primed than for unprimed words. To summarise the result it shows amnesic patients showed a greater perceptual priming effect as well as the controls.

Non-declarative memory suggests conceptual and perceptual priming belong to this form of memory. They are both similar in that amnesic patients highlight intact conceptual and perceptual priming. Warrington and Weiskrantz 1974 highlighted the finding of a double dissociation which meant patients were stronger in perceptual priming than conceptual.

Automatic retrieval in a conceptual priming task showed work was designed to explore whether priming in a conceptual priming task can occur through automatic retrieval especially under conditions of conceptual encoding. The adequacy of implicit memory (Schacter 1987) and PDP (Jacoby 1991) showed techniques for indexing, which has been questioned because the assumption is based upon the fact that priming in standard implicit paradigms occurs through pure automatic retrieval ( Graf and Mandler 1984:Schacter 1987). Priming and depth effects have been received through implicit conceptual tasks following implicit memory instructions. An example is Weldon and Coyote 1996 who emerged with evidence which suggested a chance in response strategy is not obtained with implicit instructions. Priming in studies may have been contaminated by conscious retrieval.

To summarise the above the automatic estimate from the speeded and implicit groups indicated conceptual priming through automatic retrieval (Houlihan and MacLeod 2007). These effects are supported by the depth effects on a conceptual implicit task.

Procedural memory indicates motor skills which are important for everyday life because we can for example word process and write and ride a bike. Procedural memory also known as ” skill learning” is basically learning which generalises to other stimuli.

Amnesic patients were used by Milner, Corkin, and colleagues 1960`s The research was easy, skill learning in amnesia. Indications showed that amnesic patient H.M had motor skills such as pursuit rotor and mirrir tracings even though the patient could not remember. In contrast Cermak, Lewis, Butlers and Goodglass 1975) showed amnesic patients learned the pursuit rotor quickly as healthy patients.

Mirror reading differentiated between general improvement and more specific improvement produced by re-reading the sae amount of words or sentences. Cohen and Squire 1980 reported general and specific improvements in reading mirror reversed scripts in amnesic. Other evidence highlighted improvements in reading after a delay of three months. Martone, Butters,Payne , Becker and Sax 1904 obtained evidence of general and improvement in amnesic.

Priming often occurs rapidly, whereas procedural memory “skill learning”, it is slow and gradual. Priming has shown learning related to the specific stimuli used during learning whilst on the other had procedural indicates learning related to a number of stimulus.

Both priming and procedural shows that they involve different memory systems. However evidence is unclear because tasks for the two have been very different. Poldrack, Selco, Field, and Cohen 1999 had wanted to compare both skill learning and priming within the same task. Participants entered five digits numbers into a computer keypad. Priming was assessed by the performance on non repeated strings. Skill learning and the increase in speed with repetition priming were both well described by the power function learning Poldrack et al to conclude they both involve same learning mechanism.

Both procedural and priming may highlights different memory systems involved. There is no reason why individuals who are good at skill learning should be good at priming. There is often no correlation between performance on these types of task. Schwartz and Hashtroudi 1991 used word identification task t assess priming an inverted task reading to assessing skill learning. Gupta and Cohen 2002 developed a computational model based on the assumption that skill learning and priming depend on a single mechanism. This model suggests zero for correlations between skill learning and priming.

The third aspect of implicit memory is classical conditioning highlights conditioned responses between two stimuli. Classical conditioning simply is the assumption that all behaviour is learned through association. Learn to associate a neutral stimulus with an automatic stimulus. Classical conditioning explains how abnormality can be caused by learned maladaptive emotional response.

Greenspoon 1955; Thorndike and Roc 1934) indicated learning without awareness studies. Subjects learn rules of contingencies without awareness of learning them. Studies showed methods for assessing awareness replied with positive evidence of learning without awareness (Giddan and Ericksen 1959; Krieckhaus and Ericksen 1960)

Subjects could manage various types of classical conditioned responses without awareness of conditioning contingencies (Lacey and Smith 1954). Evidence suggests subjects who were presented with letter strings had them organised according to various rules of a synthetic grammar. Reber et al 1985 reported subjects learned to identify grammatically correct strings even then there were not consciously aware of the appropriate rules. Lewicki 1986 took a difference approach which highlighted contingencies between different features of stimulus information which influenced latencies in order to respond to questions regarding the contingent features even though none of the subjects could explicitly state the nature of the contingencies.