EXPLICIT AND IMPLICIT MEMORY
Another common distinction is between explicit and implicit memory. Explicit memory (explicit memory memory with conscious awareness of the original information or the situation in which the learning occurred) involves conscious awareness of the original information or the situation in which the learning occurred, and recollection of the original information or experience that is subsequently recalled. As these experiences involve a recollective experience, Baddeley (1997), among others, prefers to refer to ‘recollective’, rather than explicit, memory. Implicit memory refers to an influence on behaviour, feelings or thoughts as a result of prior experience, but without conscious recollection of the original events. (implicit memory influence on behaviour, affect or thought as a result of prior experience but without conscious recollection of the original events) For example, if you pass the fish counter in a supermarket, you might later think of having fish for dinner without being aware that ‘fish’ had been primed by the supermarket experience. Baddeley (1997) argues that, rather than a single implicit memory system, there is probably an array of learning mechanisms that are similar in that they influence subsequent behaviour but they do not generate recollective memories.
Demonstrating the distinction
Distinctions between implicit and explicit memory are sometimes demonstrated by studies that measure priming. One task used in many priming studies is completion of word fragments (described previously for the word ‘computer’). Solutions are generally faster or more certain for recently encountered words than for new ones, even when the words are not consciously recognized. One source of evidence for the implicit/explicit distinction comes from studies involving patients with amnesia. Their amnesia means that they cannot consciously recognize words or pictures that have been previously presented, but they are nevertheless better at completing the corresponding word fragments later on (Warrington & Weiskrantz, 1968). Tulving, Schacter and Stark (1982) found a similar difference between priming and recognition test results for healthy participants not suffering from amnesia. The effect of studying a list of words on later recognition of those words declined considerably over a seven-day period, but there was no imilar decline in the effects of priming of the presented words. These studies suggest that there is a fundamental difference in the functional nature of memory, depending upon whether the test requires conscious awareness of the previous event. Jacoby (1983) provided further evidence for this view. As in the previous studies, there were two types of test: recognition (involving conscious remembering) and unconscious remembering (in this case tested via perceptual identification, i.e. identifying a word that appeared in a brief flash). Jacoby also manipulated how the words were studied. Each target word was shown with no context (e.g. ‘woman’), or shown with its opposite as a context (e.g. ‘man – woman’), or generated by the participant when shown its opposite (e.g. ‘man’ shown and ‘woman’ generated by the participant). Subsequently, the explicit memory test involved showing a mixture of target words and new words to participants and asking them to identify which words they had studied (‘Studied’ words included both read and generated words, as described above). The implicit memory test was a perceptual identification test: a mixture of targets and new words were shown very briefly (40 ms) one at a time, and the participants attempted to identify the word. on the implicit memory measure of identification and the explicit memory task of recognition. Explicit recognition improved from the ‘no context’ condition to the ‘generate’ condition, but the reverse was the case for the implicit perceptual identification task. Because the pattern of results is reversed for the two tests, it suggests that the underlying processes (i.e. implicit and explicit memories) are distinct and involve possibly independent memory mechanisms.
The nature of the task
The implicit/explicit memory distinction is often tangled up (and therefore potentially confused) with two different types of task. Some tasks require people to think about meanings and concepts; these are called concept-driven tasks. Others require people to focus on the materials in front of them; these are called data-driven tasks (Roediger, 1990). For example, if you are asked to remember words from a list that you studied, you would be explicitly recalling words and you would be likely to recall the meanings of the words as well. On the other hand, if your task was to complete word fragments, without reference to the studied list, then the influence of the study session would be implicit rather than explicit, and you would be working with the visual patterns of letters, but less so (if at all) with the meanings. It is challenging to separate the nature of the task (i.e. conceptor data-driven) and the nature of the memory being tested (i.e. explicit or implicit) (see Roediger & Blaxton, 1987). Roediger, Buckner and McDermott (1999) review the debate between explanations based upon memory systems and memory processes. The experience of remembering (or knowing) Related to the explicit/implicit memory distinction is the experience that accompanies performance on the memory task. A participant may remember having seen the item under test in a recognition experiment at the original learning trial, or they may simply ‘know’ that the word was in the original list without specifically recalling it. This ‘remember/know’ distinction was first used by Tulving (1985). He required each response in the memory test to be judged as being accompanied by an experience of remembering having studied the item, or, alternatively, of knowing that the item had been presented without specifically remembering the event. Gardiner and associates have since carried out extensive investigations of ‘remember/know’ judgements under a range of different conditions (reviewed by Gardiner & Java, 1993). A number of conditions have been shown to influence ‘remember’ and ‘know’ judgements differently. For example, semantic processing (where the meaning of the items is foremost) leads to more ‘remember’ responses than does acoustic processing (which emphasizes the sound of the words studied). In contrast, ‘know’ responses do not differ between the semantic and acoustic conditions.
Another common distinction is between explicit and implicit memory. Explicit memory (explicit memory memory with conscious awareness of the original information or the situation in which the learning occurred) involves conscious awareness of the original information or the situation in which the learning occurred, and recollection of the original information or experience that is subsequently recalled. As these experiences involve a recollective experience, Baddeley (1997), among others, prefers to refer to ‘recollective’, rather than explicit, memory. Implicit memory refers to an influence on behaviour, feelings or thoughts as a result of prior experience, but without conscious recollection of the original events. (implicit memory influence on behaviour, affect or thought as a result of prior experience but without conscious recollection of the original events) For example, if you pass the fish counter in a supermarket, you might later think of having fish for dinner without being aware that ‘fish’ had been primed by the supermarket experience. Baddeley (1997) argues that, rather than a single implicit memory system, there is probably an array of learning mechanisms that are similar in that they influence subsequent behaviour but they do not generate recollective memories.
Demonstrating the distinction
Distinctions between implicit and explicit memory are sometimes demonstrated by studies that measure priming. One task used in many priming studies is completion of word fragments (described previously for the word ‘computer’). Solutions are generally faster or more certain for recently encountered words than for new ones, even when the words are not consciously recognized. One source of evidence for the implicit/explicit distinction comes from studies involving patients with amnesia. Their amnesia means that they cannot consciously recognize words or pictures that have been previously presented, but they are nevertheless better at completing the corresponding word fragments later on (Warrington & Weiskrantz, 1968). Tulving, Schacter and Stark (1982) found a similar difference between priming and recognition test results for healthy participants not suffering from amnesia. The effect of studying a list of words on later recognition of those words declined considerably over a seven-day period, but there was no imilar decline in the effects of priming of the presented words. These studies suggest that there is a fundamental difference in the functional nature of memory, depending upon whether the test requires conscious awareness of the previous event. Jacoby (1983) provided further evidence for this view. As in the previous studies, there were two types of test: recognition (involving conscious remembering) and unconscious remembering (in this case tested via perceptual identification, i.e. identifying a word that appeared in a brief flash). Jacoby also manipulated how the words were studied. Each target word was shown with no context (e.g. ‘woman’), or shown with its opposite as a context (e.g. ‘man – woman’), or generated by the participant when shown its opposite (e.g. ‘man’ shown and ‘woman’ generated by the participant). Subsequently, the explicit memory test involved showing a mixture of target words and new words to participants and asking them to identify which words they had studied (‘Studied’ words included both read and generated words, as described above). The implicit memory test was a perceptual identification test: a mixture of targets and new words were shown very briefly (40 ms) one at a time, and the participants attempted to identify the word. on the implicit memory measure of identification and the explicit memory task of recognition. Explicit recognition improved from the ‘no context’ condition to the ‘generate’ condition, but the reverse was the case for the implicit perceptual identification task. Because the pattern of results is reversed for the two tests, it suggests that the underlying processes (i.e. implicit and explicit memories) are distinct and involve possibly independent memory mechanisms.
The nature of the task
The implicit/explicit memory distinction is often tangled up (and therefore potentially confused) with two different types of task. Some tasks require people to think about meanings and concepts; these are called concept-driven tasks. Others require people to focus on the materials in front of them; these are called data-driven tasks (Roediger, 1990). For example, if you are asked to remember words from a list that you studied, you would be explicitly recalling words and you would be likely to recall the meanings of the words as well. On the other hand, if your task was to complete word fragments, without reference to the studied list, then the influence of the study session would be implicit rather than explicit, and you would be working with the visual patterns of letters, but less so (if at all) with the meanings. It is challenging to separate the nature of the task (i.e. conceptor data-driven) and the nature of the memory being tested (i.e. explicit or implicit) (see Roediger & Blaxton, 1987). Roediger, Buckner and McDermott (1999) review the debate between explanations based upon memory systems and memory processes. The experience of remembering (or knowing) Related to the explicit/implicit memory distinction is the experience that accompanies performance on the memory task. A participant may remember having seen the item under test in a recognition experiment at the original learning trial, or they may simply ‘know’ that the word was in the original list without specifically recalling it. This ‘remember/know’ distinction was first used by Tulving (1985). He required each response in the memory test to be judged as being accompanied by an experience of remembering having studied the item, or, alternatively, of knowing that the item had been presented without specifically remembering the event. Gardiner and associates have since carried out extensive investigations of ‘remember/know’ judgements under a range of different conditions (reviewed by Gardiner & Java, 1993). A number of conditions have been shown to influence ‘remember’ and ‘know’ judgements differently. For example, semantic processing (where the meaning of the items is foremost) leads to more ‘remember’ responses than does acoustic processing (which emphasizes the sound of the words studied). In contrast, ‘know’ responses do not differ between the semantic and acoustic conditions.
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