Feature frequency effects in recognition memory.

Modulation of the word frequency effect in recognition memory after an unrelated lexical decision task

Encoding time and the mirror effect in recognition memory: Evidence from eyetracking

Operating characteristics were used to assess the importance of word-frequency and word-length in recognition memory. It was much easier for Ss to distinguish between old and new rare words than between old and new common words. Rare (but not common) words were easier to recognize when they were polysyllabic than when they were not.

Rehearsal and the word frequency effect in recognition memory

Experiment 1 confirmed previous findings that common words are more recallable than are rare words when the 2 kinds of words are presented in separate lists but not when they are presented in the same list. Experiment 2 showed much the same pattern when an orienting task was performed during word presentation. In Experiment 3 common words were found to be more recallable than rare words even for mixed lists when no warning was given of the memory test, although the effect was less pronounced than for pure lists. In Experiment 4 stronger measures were taken to preclude anticipation of the memory test, and the effect of word commonness was found to be just as pronounced with mixed lists as it was with pure lists. It was suggested that lists are studied in a way believed to optimize recall and that mixed lists foster a strategy of favoring the rare words.

This chapter examines some psycholinguistic issues raised in the study of language understanding. Questions concerning the structure of the mental lexicon and the nature of the computations that allow access to information stored in this lexicon are addressed. Research using the metaphor of lexical space and exploiting the lexical databases for Dutch and English is presented. The analysis of the similarity neighborhoods of words of different frequencies revealed a surprising pattern; common words have more neighbors than rare words and these neighbors are more frequent than those of rare words. This finding, when confronted with the word frequency effect, creates an apparent paradox that this paper attempts to resolve.

Possible determinants of the word-frequency effect (WFE), that is, the finding that lowfrequency (LF) words are recognized more accurately than high-frequency (HF) words, are evaluated. Three studies examined the view that, since HF words have more meanings than LF words, it is less likely that the word sense tagged at time of presentation will be accessed at time of test and a correct response will be made. To ensure the same word sense was accessed at time of presentation and time of test in the case of both HF and LF words, sentence contexts used during presentation were combined with cuing procedures at time of test. Recognition performance improved, but the WFE was unaltered even when the identical sentence context was used during presentation and test. A fourth study considered GlarLzer and Bowles’ (19761 suggestion that associates of both HF and LF words tend to be HF words that are (1)likely to be activated and derivatively encoded during presentation and (2) likely to include a number of distractors from the recognition test sufficient to impair performance on HF words. Analysis of associative responses of subjects to HF and LF words, and the errors they made, support strongly such an interference-type interpretation of the WFE.

The effects of word frequency and context variability in cued recall

Attention/likelihood theory has been used to explain the mirror effect in recognition memory. The theory also predicts that any manipulation that affects the recognition of old items will also affect recognition of the new items-more specifically, that all the underlying distributions will move and that they will move symmetrically on the decision axis. In five experiments, we tested this prediction. The first two experiments used encoding tasks during study to change recognition performance for high- and low-frequency words. The results show symmetrical dispersion of the underlying distributions. The final three experiments used repetition to increase recognition performance. Repetition produced a symmetrical pattern of movement that was different from that produced by encoding task. This pattern is, however, also covered by attention/likelihood theory. A further extension of the theory was used to predict response times.

The word frequency effect (WFE) has been taken as evidence that recall and recognition are in some way fundamentally different. Consequently, most models assume that recall and recognition operate via very different retrieval mechanisms. Experiment 1 showed that the WFE reverses for associative recognition, which requires discrimination between intact test pairs and recombinations of study list words from different study pairs. Experiment 2, in which word triples were used, revealed an interaction between word frequency and test type: for item recognition, performance was better for low-frequency words; however, for associative recognition and free recall, performance was better for high-frequency words. In Experiment 3, item recognition was tested: although overall performance was better for low-frequency words, the recognition advantage for items in intact pairs was larger for high-frequency words, suggesting two components in recognition memory. These results imply common mechanisms in recall and recognition. Theoretical implications are discussed within the framework of the SAM model.

List composition effects in lexical decision and recognition memory

Although the majority of research on human memory has concentrated on a person's ability to recall or recognize items as having been presented in a particular situation, the effects of memory are also revealed in a person's performance of a perceptual task. Prior experience with material can make that material more easily identified or comprehended in perceptually difficult situations. Unlike with standard retention tests, effects of prior experience on a perceptual task do not logically require that a person be aware that he or she is remembering. Indeed, amnesic patients purportedly show effects of practice in their subsequent performance of a perceptual or motor task even though they profess that they do not remember having engaged in that prior experience. The experiments that are reported were designed to explore the relationship between the more aware autobiographical form of memory that is measured by a recognition memory test and the less aware form of memory that is expressed in perceptual learning. Comparisons of effects on perceptual learning and recognition memory reveal two classes of variables. Variables such as the level of processing of words during study influenced recognition memory, although they had no effect on subsequent perceptual recognition. A study presentation of a word had as large an effect on its later perceptual recognition when recognition memory performance was very poor as it did when recognition memory performance was near perfect. In contrast, variables such as the number and the spacing of repetitions produced parallel effects on perceptual recognition and recognition memory. Following Mandler and others, it is suggested that there are two bases for recognition memory. If an item is readily perceived so that it seems to "jump out" from the page, a person is likely to judge that he or she has previously seen the item in the experimental situation. Variables that influence ease of perceptual recognition, then, can also have an effect on recognition memory, so parallel effects are found. The second basis for recognition memory involves elaboration of a word's study context and depends on such factors as level of processing during study--factors that are not important for perceptual recognition of isolated words. Comparisons of perceptual recognition and recognition memory are shown to be useful for determining how a variable has its effect. Effects of study on perceptual recognition appear to be totally due to memory for physical or graphemic information. Results reported are also relevant to theories of perceptual learning. A single presentation of an item is shown to have large and long-lasting effects on its later perceptual recognition. At least partially, effects of study on perceptual recognition depend on the same variables as do effects on more standard memory tests.

When old/new recognition memory is tested with equal numbers of studied and nonstudied items and no rewards or instructions that favour one response over the other, there is no obvious reason for response bias. In line with this, Canadian undergraduates have shown, on average, a neutral response bias when we tested them on recognition of common English words. By contrast, most subjects we have tested on recognition of richly detailed images have shown a conservative bias: they more often erred by missing a studied image than by judging a nonstudied image as studied. Here, in an effort to better understand these materials-based bias effects (MBBEs), we examined changes in hit and false alarm (FA) rates (and in sensitivity and bias) from the first to fourth quartile of a recognition memory test in eight experiments in which undergraduates studied words and/or images of paintings. Response bias for images tended to increase across quartiles, whereas bias for words showed no consistent pattern across quartiles. This pattern could be described as an increase in the MBBE over the course of the test, but the underlying patterns for hits and FAs are not easily reconciled with this interpretation. Hit rates decreased over the course of the test for both materials types, with that decline tending to be steeper for images than words. For words, FA rates tended to increase across quartiles, whereas for paintings FA rates did not increase across quartiles. We discuss implications of these findings for theoretical accounts of the MBBE.

Ketamine is a noncompetitive N-methyl-D-aspartate (NMDA) antagonist. Given the purported role of the NMDA receptor in long-term potentiation, the primary purpose of the present study was to further understand the dose-related effects of ketamine on memory. The study was also designed to provide information about the relative effects of ketamine on memory versus nonmemory effects and to more fully characterize ketamine's overall pattern and time course of effects. Single intramuscular injections of ketamine (0.2 mg/kg, 0.4 mg/kg) were administered to 18 healthy adult volunteers using a double-blind, placebo-controlled, crossover design. Word lists were used to evaluate episodic memory (free recall, recognition memory, source memory) and metamemory. Working memory, time estimation, psychomotor performance, and subjective effects were assessed repeatedly for 5 hours after drug administration. Ketamine selectively impaired encoding (as measured by free recall) while sparing retrieval, working memory while sparing attention, and digit symbol substitution task speed while sparing accuracy. Ketamine did not significantly impair recognition or source memory, metamemory, or time estimation. There were no hallucinations or increases in mystical experiences with ketamine. Memory measures were less sensitive to ketamine effects than subjective or psychomotor measures. Subjective effects lasted longer than memory and most psychomotor impairments. Ketamine produces selective, transient, dose- and time-related effects. In conjunction with previous studies of drugs with different mechanisms of actions, the observed selectivity of effects enhances the understanding of the pharmacological mechanisms underlying memory, attention, psychomotor performance, and subjective experience.

In order to examine the relation between recognition memory and priming effects, we have tracked the recovery of recognition memory and word completion ability during the hours after individual treatment given as part of a prescribed course of electroconvulsive therapy (ECT). Recognition memory was tested by a three-alternative, forced-choice method. In the word completion test, the initial letters of previously presented words were given as cues, and subjects were asked to complete each cue to form the first word that came to mind. Patients receiving bilateral ECT markedly improved their recognition memory performance 45 min to 9 hr after treatment. Word completion performance was normal at 45 min after treatment and did not change thereafter. Despite exhibiting normal priming effects, patients prescribed bilateral ECT scored at chance levels on recognition tests given 45 min after treatment. These findings support the view that recognition memory and priming are independent memory processes, and they suggest that the processes that support priming make little if any contribution to recognition memory. The results are considered in terms of neuropsychological evidence from amnesic patients for the existence of multiple memory systems.