Effects of age on state of awareness following implicit and explicit word-association tasks.

Younger and older participants did word-association tasks after implicit and explicit instructions and a read-generate study manipulation. No age differences were shown in the implicit version of the test. A generation effect for both age groups suggested that word-association priming can be classified as a conceptually driven task and a new task at which older adults show a relatively preserved memory function. However, the younger group did better on the explicit test in the generate condition. Participants were asked to examine their implicitly produced responses to make them accessible to conscious retrieval. Remember (R) and Know (K) measures of conscious awareness were applied to both postimplicit and postexplicit word-association responses. Age and awareness showed opposite effects in postimplicit retrieval. Younger participants tended to make more R responses than did the older adults, and K responses did not vary with age, but the older group was unaware of more primed items as study list members. Age differences were also shown in R but not K responses after word-association cued recall.

Repetition of previously novel melodies sometimes increases both remember and know responses in recognition memory.

Recognition memory for previously novel melodies was tested in three experiments in which subjects usedremember andknow responses to report experiences of recollection, or of familiarity in the absence of recollection, for each melody they recognized. Some of the melodies were taken from Polish folk songs and presented vocally, but without the words. Others were taken from obscure pieces of classical music, presented as single-line melodies. Prior to the test, the melodies were repeated for varying numbers of study trials. Repetition of the Polish melodies increased both remember and know responses, while repetition of classical melodies increased remember but not know responses. When subjects were instructed to report guesses, guess responses were inversely related to remember and know responses and there were more guesses to lures than to targets. These findings establish that remembering and knowing are fully independent functionally and, by the same token, they provide further evidence against the idea that response exclusivity causes increases in remembering to force decreases in knowing. The findings also suggest that simultaneous increases in remembering and knowing occurred because the Polish melodies came from a genre for which the subjects had relatively little previous experience.

Involuntary conscious memory and the method of opposition.

Priming in an indirect test of stem completion should reflect involuntary memory, but can be accompanied by conscious awareness of the past (involuntary conscious memory) or unaccompanied by such awareness (involuntary unconscious memory). We adapted the method of opposition developed by Jacoby, Woloshyn, and Kelley (1989) to obtain a measure of stem-completion priming that should reflect only involuntary unconscious memory. Subjects completed stems with the first word coming to mind, but wrote down a different word if the word that came to mind first had been previously encountered. Facilitatory priming was expected only when involuntary unconscious influences outweighed inhibitory effects of involuntary conscious memory, or of intentional retrieval. We observed a facilitation effect for items processed graphemically at encoding, in conjunction with an inhibition effect for items processed semantically at encoding. In contrast, a standard indirect test showed similar levels of priming following graphemic and semantic encoding, whereas a direct test showed a strong advantage of semantic over graphemic encoding. We argue that the two encoding activities produced approximately equivalent involuntary influences of memory, but that items encoded semantically were associated with involuntary conscious memory to a greater extent than were items encoded graphemically. Comparing indirect and opposition test performance can provide a quantitative index of relative levels of involuntary conscious and involuntary unconscious memory.

Effects of lorazepam upon recollective experience in recognition memory.

The effects of lorazepam (2 mg) and placebo upon recognition memory with and without conscious recollection were assessed in a cross-over study with normal volunteers. When recognising a word from study lists presented before and 1, 3 and 5 h after drug administration, subjects were required to indicate whether they could consciously recollect the word's prior occurrence or recognised it on the basis of "knowing"; in the absence of conscious recollection. Lorazepam only impaired word recognition which was accompanied by conscious recollection, and further, the level of this impairment correlated significantly with each of three different indices of subjects' arousal at the time of presentation of each list. Recognition in the absence of conscious recollection was not impaired but somewhat heightened by lorazepam, and these effects did not significantly relate to any index of arousal. These findings are interpreted as providing further support for the notion that recognition entails two distinct components, one based on contextual and associative information and related to conscious recollection, the other possibly based on a "traceless" perceptual or semantic memory system and related to feelings of knowing in the absence of conscious recollection. Implications are drawn for a contextual-encoding/retrieval account of lorazepam-induced amnesia.

Priming and aging: evidence of preserved memory function in an anagram solution task.

Priming effects in a test of anagram solution were compared with recognition memory in young and older adults. Age and a levels-of-processing study manipulation had little influence on priming in the anagram solution task, whereas significant effects of both of these variables were obtained in a recognition test. These findings extend those of previous studies which have shown little evidence of age differences in implicit memory tasks compared with those of explicit memory. Furthermore, they provide evidence for classifying anagram solution as an implicit memory test.

Forgetting in recognition memory with and without recollective experience.

Retention interval was manipulated in two recognition-memory experiments in which subjects indicated when recognizing a word whether its recognition was accompanied by some recollective experience ("remember") or whether it was recognized on the basis of familiarity without any recollective experience ("know"). Experiment 1 showed that between 10 min and 1 week, "remember" responses declined sharply from an initially higher level, whereas "know" responses remained relatively unchanged. Experiment 2 showed that between 1 week and 6 months, both kinds of responses declined at a similar, gradual rate and that despite quite low levels of performance after 6 months, both kinds of responses still gave rise to accurate discrimination between target words and lures. These findings are discussed in relationship to current ideas about multiple memory systems and processing accounts of explicit and implicit measures of retention.

Priming and aging: further evidence of preserved memory function.

Priming effects in word-stem completion were compared with cued recall in young and older adults. Cued recall showed large effects of age and also of levels of processing, but these variables had little influence on priming in word-stem completion. Free recall showed large effects of age as well as superior recall for words that had been generated rather than read at study, but priming in word-stem completion was little influenced by age, and it was greater for words that had been read at study rather than generated. These findings were interpreted as providing further evidence that age-related impairments in memory performance are greatly reduced in implicit compared with explicit tests. They also provide convergent evidence for classifying word-stem completion as a data-driven rather than conceptually driven task.

The Tulving-Wiseman law and the recognition of recallable music.

Memory for well-known musical phrases was tested first for recognition in the absence of any specific musical context and then for recall given the preceding musical phrase as a contextual cue. Recognition and recall were found to be largely, but not completely, independent. Moreover, there was no evidence of any greater dependency between recognition and recall than that previously observed in the relation between word recognition and recall, as summarized by the Tulving-Wiseman law. These findings significantly extend the range of applicability of this law.

Recollective experience in word and nonword recognition.

The functional relationship between memory and consciousness was investigated in two experiments in which subjects indicated when recognizing an item whether they could consciously recollect its prior occurrence in the study list or recognized it on some other basis, in the absence of conscious recollection. Low-frequency words, relative to high-frequency words, enhanced recognition accompanied by conscious recollection but did not influence recognition in the absence of conscious recollection. By contrast, nonwords compared with words enhanced recognition in the absence of conscious recollection and reduced recognition accompanied by conscious recollection. A third experiment showed that confidence judgments in recognizing nonword targets corresponded with recognition performance, not with recollective experience. These measures of conscious awareness therefore tap qualitatively different components of memory, not some unitary dimension such as "trace strength." The findings are interpreted as providing further support for the distinction between episodic memory and other memory systems, and also as providing more qualified support for theories that assume that recognition memory entails two components, one of which may also give rise to priming effects in implicit memory.