Unconscious influences revealed. Attention, awareness, and control.

Recent findings of dissociations between direct and indirect tests of memory and perception have renewed enthusiasm for the study of unconscious processing. The authors argue that such findings are heir to the same problems of interpretation as are earlier evidence of unconscious influences--namely, one cannot eliminate the possibility that conscious processes contaminated the measure of unconscious processes. To solve this problem, the authors define unconscious influences in terms of lack of conscious control and then describe a process dissociation procedure that yields separate quantitative estimates of the concurrent contributions of unconscious and consciously controlled processing to task performance. This technique allows one to go beyond demonstrating the existence of unconscious processes to examine factors that determine their magnitude.     

Fluency versus conscious recollection in the word completion performance of amnesic patients

To examine the relative contribution of fluency and recollection to the word completion performance of amnesics, we administered a task in which patients were told specifically not to utilize previously presented words during stem completion (an Exclusion condition). This condition was contrasted with a standard word completion task in which patients were encouraged simply to complete the stem with the first word that came to mind (an Inclusion condition). Since the exclusion condition necessitated controlled respecification of the initial presentation, it was hypothesized that amnesics would be less able than controls to exclude study list items. Consistent with this hypothesis, the results indicated that the amnesics' performance, unlike that of the alcoholic controls, did not significantly differ as a function of task condition. To examine whether amnesics' conscious recollection could be enhanced, Experiment 2 presented the study list five times. The amnesics now were able to exclude a significant number of items from the study list; however, they still did so considerably less frequently than alcoholic controls. For the alcoholic controls, increasing the number of study trials had little additional effect on their exclusion performance, but it significantly enhanced their inclusion performance. Taken together, these findings suggest that for control subjects, word completion performance is likely mediated by a combination of fluency and recollection, while for amnesic patients, performance is almost exclusively based on the fluency with which an item comes to mind.     

Specific word transfer as a measure of processing in the word-superiority paradigm

Explanations of context effects in the Reicher-Wheeler task and the letter-identification task appeal to word-based processing, yet these tasks provide no explicit measure of word processing. An experiment is reported which was designed to investigate the use of transfer in the word-identification task as a measure of word-based processing in letter-identification tasks. It was found that encoding manipulations that determined whether a word-superiority effect was or was not found in a letter-identification task (e.g., Thompson & Massaro, 1973) also determined whether transfer was or was not found in a subsequent word-identification task. The results of the experiment are discussed in terms of the utility of using transfer experiments as converging evidence about the presence and/or absence of processes that cannot be directly measured in other experimental paradigms.     

Perceptual enhancement: persistent effects of an experience

Presenting a word enhances its later perceptual identification. This article focuses on the relation between this effect on perception and recognition memory. Prior experiments have revealed that perceptual enhancement is independent of recognition memory and have led to the two types of task being identified with separate memory systems. In contrast, the present experiments reveal parallel effects on the two types of task. Perceptual enhancement persists over days but, like recognition memory, is influenced by manipulations of retrieval conditions. I conclude that both perceptual and memory tasks rely on the retrieval of memory for whole prior processing episodes but can differ in terms of the number and nature of retrieval cues that they provide. I describe perception and memory within a common framework.     

Proactive interference, accessibility bias, and process dissociations: valid subjective reports of memory

Proactive interference was assessed with a variant of the process-dissociation procedure, which separates effects of habit (accessibility bias) and recollection (discriminability). In three cued-recall experiments, proactive interference was shown to be an effect of bias rather than an effect on actual remembering. Divided attention, age, and study duration selectively influenced the recollection parameter, whereas training probability selectively influenced the habit parameter. Furthermore, in Experiments 2 and 3, subjective reports of remembering were highly correlated with, and nearly identical to, objective estimates of recollection gained from the process-dissociation procedure. The authors discuss the relevance of the results to theories of proactive interference and argue that older adults' greater susceptibility to interference effects is sometimes caused by an inability to recollect rather than by an inability to inhibit a preponderant response.     

Frequent false hearing by older adults: the role of age differences in metacognition

In two experiments testing age differences in the subjective experience of listening, which we call meta-audition, young and older adults were first trained to learn pairs of semantic associates. Following training, both groups were tested on identification of words presented in noise, with the critical manipulation being whether the target item was congruent, incongruent, or neutral with respect to prior training. Results of both experiments revealed that older adults compared to young adults were more prone to "false hearing," defined as mistaken high confidence in the accuracy of perception when a spoken word had been misperceived. These results were obtained even when performance was equated across age groups on control items by reducing the noise level for older adults. Such false hearing is shown to reflect older adults' heavier reliance on context. Findings suggest that older adults' greater ability to benefit from semantic context reflects their bias to respond consistently with the context, rather than their greater skill in using context. Procedures employed are unique in measuring the subjective experience of hearing as well as its accuracy. Both theoretical and applied implications of the findings are discussed. Convergence of results with those showing higher false memory, and false seeing are interpreted as showing that older adults are less able to constrain their processing in ways that are optimal for performance of a current task. That lessened constraint may be associated with decline in frontal-lobe functioning.     

The effects of age and divided attention on spontaneous recognition

Studies of recognition typically involve tests in which the participant’s memory for a stimulus is directly questioned. There are occasions however, in which memory occurs more spontaneously (e.g., an acquaintance seeming familiar out of context). Spontaneous recognition was investigated in a novel paradigm involving study of pictures and words followed by recognition judgments on stimuli with an old or new word superimposed over an old or new picture. Participants were instructed to make their recognition decision on either the picture or word and to ignore the distracting stimulus. Spontaneous recognition was measured as the influence of old vs. new distracters on target recognition. Across two experiments, older adults and younger adults placed under divided-attention showed a greater tendency to spontaneously recognize old distracters as compared to full-attention younger adults. The occurrence of spontaneous recognition is discussed in relation to ability to constrain retrieval to goal-relevant information.     

Experience with proactive interference diminishes its effects: mechanisms of change

In three experiments, we examined the mechanisms by which prior experience with proactive interference (PI) diminished its effects. Cued recall tasks conforming to an A–B, A–D paradigm were used to induce PI effects. Experiment 1 showed that reduced PI was not due to a reduction in attention to the source of PI. Experiment 2 revealed that participants’ awareness of PI effects on memory performance increased with experience, resulting in a shift in encoding processes. Experiment 3 demonstrated that changes in encoding provided additional support for recollection that further enhanced participants’ ability to constrain their retrieval processing to the appropriate source of information at the time of test. These results can be interpreted as showing that experience with PI enhances awareness of its effects and allows individuals to adjust their learning and retrieval strategies to compensate for such effects.