Recognition memory decisions made with short- and long-term retrieval

In the present research, we produce a coherent account of the storage and retrieval processes in short- and long-term event memory, and long-term knowledge, that produce response accuracy and response time in a wide variety of conditions in our studies of recognition memory. Two to nine pictures are studied sequentially followed by a target or foil test picture in four conditions used in Nosofsky et al. Journal of Experimental Psychology: Learning, Memory, and Cognition, 47, 316-342, (2021) and in our new paradigm: VM: target and foil responses to a given stimulus change from trial to trial; CM: the responses do not change from trial to trial; AN: every trial uses new stimuli; MIXED: combinations of VM, CN, and AN occur on each trial. In the new paradigm a given picture is equally often tested as old or new, but only in CM is the response key the same and learnable. Our model has components that have appeared in a variety of prior accounts, including learning and familiarity, but are given support by our demonstration that accuracy and response time data from a large variety of conditions can be predicted by these processes acting together, with parameter values that largely are unchanged. A longer version of this article, containing information not found here due to space, is available online  https://doi.org/10.31234/osf.io/h8msp .The avalibility of the data (supplement materials), info and link is attached at the end section ( https://psyarxiv.com/h8msp .).

Against naïve induction from experimental data

This commentary argues against the indictment of current experimental practices such as piecemeal testing, and the proposed integrated experiment design (IED) approach, which we see as yet another attempt at automating scientific thinking. We identify a number of undesirable features of IED that lead us to believe that its broad application will hinder scientific progress.

The distinction between long-term knowledge and short-term control processes is valid and useful

The binary distinction De Neys questions has been put forward many times since the beginnings of psychology, in slightly different forms and under different names. It has proved enormously useful and has received detailed empirical support and careful modeling. At heart the distinction is that between knowledge in long-term memory and control processes in short-term memory.

"Is it Reasonable to Study Decision-Making Quantitatively?"

Scientists studying decision-making often provide a set of choices, each specified with values or distributions of values, and probabilities or distributions of probabilities. For example, "Would you prefer $100 with probability 1.0 or $1 with probability .9 and $1,000 with probability 0.1?" Other decision research examines choices made in the absence of most quantitative information; for example, "Would you prefer a Ford now or a Porsche a year from now?," "Which food would you prefer," but models the findings with precise quantitative assumptions. Yet other research does neither; for example, modeling verbally stated choices with verbally stated heuristics. This article asks about the relevance of the first two research approaches for much of the decision-making made in life. The use of quantitative research and modeling is unsurprising, given that this approach underlies most of science. In life, values and probabilities are almost always partly or wholly vague and qualitative rather than quantitative. For example, when deciding which house to buy, there are relevant features such as size, color, neighborhood schools, construction materials, attractiveness, and many more, but the decision-maker finds it difficult and of little use to assign these precise values or weights. Nonetheless, humans have evolved to make decisions in such vaguely specified settings. I provide an example showing how a very high degree of uncertainty can defeat the application of quantitative decision-making, but such a demonstration is not critical if quantitative research and modeling produce a good understanding of and a good approximation to decision-making in the natural environment. This perspective addresses these issues.

Modeling short- and long-term memory contributions to recent event recognition

Participants gave recognition judgments for short lists of pictures of everyday objects. Pictures in a given list were an equal mixture of three types that varied according to the way they were used as targets and foils earlier in the same session. Under consistent-mapping (CM), targets and foils never switch roles; under varied-mapping (VM), targets and foils switch roles randomly across trials; whereas all-new (AN) items are novel on each trial of the experiment. Past research has shown that markedly enhanced performance occurs in CM conditions, leading to conclusions that item-response learning takes place in CM, perhaps automatically. However, almost all past research has compared CM, VM, and AN performance in between-blocks designs in which participants may adopt different cognitive strategies and criterion settings across the conditions. The present mixed-list design holds constant the strategy and criterion settings that are used for CM, VM, and AN items, and produced patterns of performance dramatically different than those observed in pure-list control conditions. We develop an extended version of an exemplar-based random-walk model of probe recognition to account for the major qualitative effects in the data. The data and the modeling provide evidence for strong item-response learning for CM foils but weak item-response learning for CM targets. We consider possible explanations for these effects in our General Discussion. (PsycInfo Database Record (c) 2021 APA, all rights reserved).

Scientific progress despite irreproducibility: A seeming paradox

It appears paradoxical that science is producing outstanding new results and theories at a rapid rate at the same time that researchers are identifying serious problems in the practice of science that cause many reports to be irreproducible and invalid. Certainly, the practice of science needs to be improved, and scientists are now pursuing this goal. However, in this perspective, we argue that this seeming paradox is not new, has always been part of the way science works, and likely will remain so. We first introduce the paradox. We then review a wide range of challenges that appear to make scientific success difficult. Next, we describe the factors that make science work-in the past, present, and presumably also in the future. We then suggest that remedies for the present practice of science need to be applied selectively so as not to slow progress and illustrate with a few examples. We conclude with arguments that communication of science needs to emphasize not just problems but the enormous successes and benefits that science has brought and is now bringing to all elements of modern society.

The development of automaticity in short-term memory search: Item-response learning and category learning

In short-term-memory (STM)-search tasks, observers judge whether a test probe was present in a short list of study items. Here we investigated the long-term learning mechanisms that lead to the highly efficient STM-search performance observed under conditions of consistent-mapping (CM) training, in which targets and foils never switch roles across trials. In item-response learning, subjects learn long-term mappings between individual items and target versus foil responses. In category learning, subjects learn high-level codes corresponding to separate sets of items and learn to attach old versus new responses to these category codes. To distinguish between these 2 forms of learning, we tested subjects in categorized varied mapping (CV) conditions: There were 2 distinct categories of items, but the assignment of categories to target versus foil responses varied across trials. In cases involving arbitrary categories, CV performance closely resembled standard varied-mapping performance without categories and departed dramatically from CM performance, supporting the item-response-learning hypothesis. In cases involving prelearned categories, CV performance resembled CM performance, as long as there was sufficient practice or steps taken to reduce trial-to-trial category-switching costs. This pattern of results supports the category-coding hypothesis for sufficiently well-learned categories. Thus, item-response learning occurs rapidly and is used early in CM training; category learning is much slower but is eventually adopted and is used to increase the efficiency of search beyond that available from item-response learning. (PsycINFO Database Record

A Bootstrapping Model of Frequency and Context Effects in Word Learning

Prior research has shown that people can learn many nouns (i.e., word-object mappings) from a short series of ambiguous situations containing multiple words and objects. For successful cross-situational learning, people must approximately track which words and referents co-occur most frequently. This study investigates the effects of allowing some word-referent pairs to appear more frequently than others, as is true in real-world learning environments. Surprisingly, high-frequency pairs are not always learned better, but can also boost learning of other pairs. Using a recent associative model (Kachergis, Yu, & Shiffrin, 2012), we explain how mixing pairs of different frequencies can bootstrap late learning of the low-frequency pairs based on early learning of higher frequency pairs. We also manipulate contextual diversity, the number of pairs a given pair appears with across training, since it is naturalistically confounded with frequency. The associative model has competing familiarity and uncertainty biases, and their interaction is able to capture the individual and combined effects of frequency and contextual diversity on human learning. Two other recent word-learning models do not account for the behavioral findings.

The Dilution Effect and Information Integration in Perceptual Decision Making

In cognitive science there is a seeming paradox: On the one hand, studies of human judgment and decision making have repeatedly shown that people systematically violate optimal behavior when integrating information from multiple sources. On the other hand, optimal models, often Bayesian, have been successful at accounting for information integration in fields such as categorization, memory, and perception. This apparent conflict could be due, in part, to different materials and designs that lead to differences in the nature of processing. Stimuli that require controlled integration of information, such as the quantitative or linguistic information (commonly found in judgment studies), may lead to suboptimal performance. In contrast, perceptual stimuli may lend themselves to automatic processing, resulting in integration that is closer to optimal. We tested this hypothesis with an experiment in which participants categorized faces based on resemblance to a family patriarch. The amount of evidence contained in the top and bottom halves of each test face was independently manipulated. These data allow us to investigate a canonical example of sub-optimal information integration from the judgment and decision making literature, the dilution effect. Splitting the top and bottom halves of a face, a manipulation meant to encourage controlled integration of information, produced farther from optimal behavior and larger dilution effects. The Multi-component Information Accumulation model, a hybrid optimal/averaging model of information integration, successfully accounts for key accuracy, response time, and dilution effects.

Perspectives on modeling in cognitive science

This commentary gives a personal perspective on modeling and modeling developments in cognitive science, starting in the 1950s, but focusing on the author's personal views of modeling since training in the late 1960s, and particularly focusing on advances since the official founding of the Cognitive Science Society. The range and variety of modeling approaches in use today are remarkable, and for many, bewildering. Yet to come to anything approaching adequate insights into the infinitely complex fields of mind, brain, and intelligent systems, an extremely wide array of modeling approaches is vital and necessary.

Familiarity and categorization processes in memory search

A fundamental distinction in tasks of memory search is whether items receive varied mappings (targets and distractors switch roles across trials) or consistent mappings (targets and distractors never switch roles). The type of mapping often produces markedly different performance patterns, but formal memory-based models that account quantitatively for detailed aspects of the results have not yet been developed and evaluated. Experiments were conducted to test a modern exemplar-retrieval model on its ability to account for memory-search performance involving a wide range of memory-set sizes in both varied-mapping (VM) and consistent-mapping (CM) probe-recognition tasks. The model formalized the idea that both familiarity-based and categorization-based processes operate. The model was required to fit detailed response-time (RT) distributions of individual, highly practiced subjects. A key manipulation involved the repetition of negative probes across trials. This manipulation produced a dramatic dissociation: False-alarm rates increased and correct-rejection RTs got longer in VM, but not in CM. The qualitative pattern of results and modeling analyses provided evidence for a strong form of categorization-based processing in CM, in which observers made use of the membership of negative probes in the "new" category to make old-new recognition decisions.

Cross-situational word learning is both implicit and strategic

For decades, implicit learning researchers have examined a variety of cognitive tasks in which people seem to automatically extract structure from the environment. Similarly, recent statistical learning studies have shown that people can learn word-object mappings from the repeated co-occurrence of words and objects in individually ambiguous situations. In light of this, the goal of the present paper is to investigate whether adult cross-situational learners require an explicit effort to learn word-object mappings, or if it may take place incidentally, only requiring attention to the stimuli. In two implicit learning experiments with incidental tasks directing participants' attention to different aspects of the stimuli, we found evidence of learning, suggesting that cross-situational learning mechanisms can operate incidentally, without explicit effort. However, performance was superior under explicit study instructions, indicating that strategic processes also play a role. Moreover, performance under instruction to learn word meanings did not differ from performance at counting co-occurrences, which may indicate these tasks engage similar strategies.

An exemplar-familiarity model predicts short-term and long-term probe recognition across diverse forms of memory search

Experiments were conducted to test a modern exemplar-familiarity model on its ability to account for both short-term and long-term probe recognition within the same memory-search paradigm. Also, making connections to the literature on attention and visual search, the model was used to interpret differences in probe-recognition performance across diverse conditions that manipulated relations between targets and foils across trials. Subjects saw lists of from 1 to 16 items followed by a single item recognition probe. In a varied-mapping condition, targets and foils could switch roles across trials; in a consistent-mapping condition, targets and foils never switched roles; and in an all-new condition, on each trial a completely new set of items formed the memory set. In the varied-mapping and all-new conditions, mean correct response times (RTs) and error proportions were curvilinear increasing functions of memory set size, with the RT results closely resembling ones from hybrid visual-memory search experiments reported by Wolfe (2012). In the consistent-mapping condition, new-probe RTs were invariant with set size, whereas old-probe RTs increased slightly with increasing study-test lag. With appropriate choice of psychologically interpretable free parameters, the model accounted well for the complete set of results. The work provides support for the hypothesis that a common set of processes involving exemplar-based familiarity may govern long-term and short-term probe recognition across wide varieties of memory- search conditions.

Discrete-slots models of visual working-memory response times

Much recent research has aimed to establish whether visual working memory (WM) is better characterized by a limited number of discrete all-or-none slots or by a continuous sharing of memory resources. To date, however, researchers have not considered the response-time (RT) predictions of discrete-slots versus shared-resources models. To complement the past research in this field, we formalize a family of mixed-state, discrete-slots models for explaining choice and RTs in tasks of visual WM change detection. In the tasks under investigation, a small set of visual items is presented, followed by a test item in 1 of the studied positions for which a change judgment must be made. According to the models, if the studied item in that position is retained in 1 of the discrete slots, then a memory-based evidence-accumulation process determines the choice and the RT; if the studied item in that position is missing, then a guessing-based accumulation process operates. Observed RT distributions are therefore theorized to arise as probabilistic mixtures of the memory-based and guessing distributions. We formalize an analogous set of continuous shared-resources models. The model classes are tested on individual subjects with both qualitative contrasts and quantitative fits to RT-distribution data. The discrete-slots models provide much better qualitative and quantitative accounts of the RT and choice data than do the shared-resources models, although there is some evidence for "slots plus resources" when memory set size is very small.

Actively learning object names across ambiguous situations

Previous research shows that people can use the co-occurrence of words and objects in ambiguous situations (i.e., containing multiple words and objects) to learn word meanings during a brief passive training period (Yu & Smith, 2007). However, learners in the world are not completely passive but can affect how their environment is structured by moving their heads, eyes, and even objects. These actions can indicate attention to a language teacher, who may then be more likely to name the attended objects. Using a novel active learning paradigm in which learners choose which four objects they would like to see named on each successive trial, this study asks whether active learning is superior to passive learning in a cross-situational word learning context. Finding that learners perform better in active learning, we investigate the strategies and discover that most learners use immediate repetition to disambiguate pairings. Unexpectedly, we find that learners who repeat only one pair per trial--an easy way to infer this pair-perform worse than those who repeat multiple pairs per trial. Using a working memory extension to an associative model of word learning with uncertainty and familiarity biases, we investigate individual differences that correlate with these assorted strategies.

Sources of interference in recognition testing

Recognition memory accuracy is harmed by prior testing (a.k.a., output interference [OI]; Tulving & Arbuckle, 1966). In several experiments, we interpolated various tasks between recognition test trials. The stimuli and the tasks were more similar (lexical decision [LD] of words and nonwords) or less similar (gender identification of male and female faces) to the stimuli and task used in recognition testing. Not only did the similarity between the interpolated and recognition tasks not affect recognition accuracy but performance of the interpolated task caused no interference in subsequent recognition testing. Only the addition of recognition trials caused OI. When we presented a block of LD trials or gender identification trials before the recognition test, a decrease in accuracy was observed in the subsequent recognition tests. These results suggest a distinction between temporal context and task context, such that recognition memory performance is determined by the salience of the context cues, and the use of temporal context cues is associated with OI.

The co-evolution of knowledge and event memory

We present a theoretical framework and a simplified simulation model for the co-evolution of knowledge and event memory, both termed SARKAE (Storing and Retrieving Knowledge and Events). Knowledge is formed through the accrual of individual events, a process that operates in tandem with the storage of individual event memories. In 2 studies, new knowledge about Chinese characters is trained over several weeks, different characters receiving differential training, followed by tests of episodic recognition memory, pseudo-lexical decision, and forced-choice perceptual identification. The large effects of training frequency in both studies demonstrated an important role of pure frequency in addition to differential context and differential similarity. The SARKAE theory provides a framework within which models for various tasks can be developed; we illustrate the way this could operate, and we make the verbal descriptions of the theory more precise with a simplified simulation model applied to the results.

Criterion setting and the dynamics of recognition memory

Models of recognition memory have traditionally struggled with the puzzle of criterion setting, a problem that is particularly acute in cases in which items for study and test are of widely varying types, with differing degrees of baseline familiarity and experience (e.g., words vs. random dot patterns). We present a dynamic model of the recognition process that addresses the criterion setting problem and produces joint predictions for choice and reaction time. In this model, recognition decisions are based not on the absolute value of familiarity, but on how familiarity changes over time as features are sampled from the test item. Decisions are the outcome of a race between two parallel accumulators: one that accumulates positive changes in familiarity (leading to an ''old'' decision) and another that accumulates negative changes (leading to a ''new'' decision). Simulations with this model make realistic predictions for recognition performance and latency regardless of the baseline familiarity of study and test items.

Overcoming the Negative Consequences of Interference From Recognition Memory Testing

Theories of why humans forget have been challenged by the newly discovered list-length/output-interference paradox, in which—under certain testing conditions—learning is not harmed by the amount of verbal material studied, whereas retrieval of that material becomes more difficult with increases in the number of items tested. The latter finding is known as output interference, and the results of the experiment reported here indicate that a release from output interference is obtained when the nature of the items is changed during testing. Specifically, when participants are asked to recognize items from two categories, output interference is minimized when items from each category are tested separately in large blocks. This finding supports models of forgetting that assume interference arises from information about the to-be-learned material that is stored in memory; in contrast, this finding is difficult to explain using models that assume forgetting is the result only of changing context.

Visual free recall

Lists of complex pictures, not easily encoded verbally, were presented to subjects who recalled them by writing brief descriptions. The lists were 10, 20, and 40 pictures in length. Recall failed to show the primacy and recency effects seen with verbal materials, but was lower for pictures in longer lists. This argues for serial-position effects based in short-term memory and independent list-length effects arising during retrieval from long-term memory.

Prime diagnosticity in short-term repetition priming: is primed evidence discounted, even when it reliably indicates the correct answer?

The authors conducted 4 repetition priming experiments that manipulated prime duration and prime diagnosticity in a visual forced-choice perceptual identification task. The strength and direction of prime diagnosticity produced marked effects on identification accuracy, but those effects were resistant to subsequent changes of diagnosticity. Participants learned to associate different diagnosticities with primes of different durations but not with primes presented in different colors. Regardless of prime diagnosticity, preference for a primed alternative covaried negatively with prime duration, suggesting that even for diagnostic primes, evidence discounting remains an important factor. A computational model, with the assumption that adaptation to the statistics of the experiment modulates the level of evidence discounting, accounted for these results.

Inducing features from visual noise

We present new experimental and mathematical techniques aimed at determining the features used in visual object recognition. We conceive of these features as the parts of an object that are treated as unitary wholes when recognizing or discriminating visual objects. For example, consider a task classifying a visual target presented in pixel noise as a "P" or a "Q". The features may correspond to particular shapes of the target letters. Two such features for "P", for example, might be a vertical line and upper-right-facing curve. The decision may be encoded in terms of particular values of such features, and an appropriate combination of these values may determine how the expression is perceived. We utilize recent advances in statistical machine learning techniques to uncover the features used by human observers.

List discrimination in associative recognition and implications for representation

Four experiments tested the predictions made by the model outlined in A. H. Criss and R. M. Shiffrin (2004b). Participants studied 2 successive lists of pairs followed by a recognition memory test for the most recent list. Some items and some pairs were repeated across the 2 lists. Critically, a given item could be repeated in the same or different type of pair. For associative recognition, performance was only affected by repetitions in the same pair type. However, in single-item recognition confusions occurred for both types of repetitions. The results are as predicted and confirm the assumption that different associative representations were stored even when the same token repeated in different pair types, whereas similar item representations were used regardless of pair type.

The "one-shot" hypothesis for context storage

In 3 experiments motivated by the implicit memory literature, the authors investigated the effects of different strengthening operations on the list strength effect (LSE) for explicit free recall, an effect posited by R. M. Shiffrin, R. Ratcliff, and S. E. Clark (1990) to be due to context cuing. According to the one-shot hypothesis, a fixed amount of context is stored when an item is studied for at least 1 or 2 s. Beyond the initial context storage, increases in study time or different orienting tasks do not influence the amount of context that is stored, and thus only spaced repetitions should produce a positive LSE. Consistent with prior findings, spaced repetitions always produced a positive LSE, but increases in depth of processing, study time, and massed repetitions did not. A model implements the one-shot hypothesis, and a role for context storage as a link between episodic and semantic memory is discussed.

Interactions between study task, study time, and the low-frequency hit rate advantage in recognition memory

In studies of episodic recognition memory, low-frequency words (LF) have higher hit rates (HR) and lower false alarm rates (FAR) than do high-frequency words (HF), which is known as the mirror pattern. A few findings have suggested that requiring a task at study may reduce or eliminate the LF-HR advantage without altering the LF-FAR effect. Other studies have suggested that the size of the LF-HR advantage interacts with study time. To explore such findings more thoroughly and relate them to theory, the authors conducted 5 experiments, varying study time and study task. The full mirror pattern was found only in 2 cases: the standard condition requiring study for a later memory test and a condition requiring a judgment about unusual letters. The authors explain their findings in terms of the encoding of distinctive features and discuss the implications for current theories of recognition memory and the word frequency effect.

Efficiently measuring recognition performance with sparse data

We examine methods for measuring performance in signal-detection-like tasks when each participant provides only a few observations. Monte Carlo simulations demonstrate that standard statistical techniques applied to a d' analysis can lead to large numbers of Type I errors (incorrectly rejecting a hypothesis of no difference). Various statistical methods were compared in terms of their Type I and Type II error (incorrectly accepting a hypothesis of no difference) rates. Our conclusions are the same whether these two types of errors are weighted equally or Type I errors are weighted more heavily. The most promising method is to combine an aggregate d' measure with a percentile bootstrap confidence interval, a computer-intensive nonparametric method of statistical inference. Researchers who prefer statistical techniques more commonly used in psychology, such as a repeated measures t test, should use gamma (Goodman & Kruskal, 1954), since it performs slightly better than or nearly as well as d'. In general, when repeated measures t tests are used, gamma is more conservative than d': It makes more Type II errors, but its Type I error rate tends to be much closer to that of the traditional .05 alpha level. It is somewhat surprising that gamma performs as well as it does, given that the simulations that generated the hypothetical data conformed completely to the d' model. Analyses in which H--FA was used had the highest Type I error rates. Detailed simulation results can be downloaded from www.psychonomic.org/archive/Schooler-BRM-2004.zip.

Confusion and Compensation in Visual Perception: Effects of Spatiotemporal Proximity and Selective Attention

The authors investigated spatial, temporal, and attentional manipulations in a short-term repetition priming paradigm. Brief primes produced a strong preference to choose the primed alternative, whereas long primes had the opposite effect. However, a 2nd brief presentation of a long prime produced a preference for the primed word despite the long total prime duration. These surprising results are explained by a computational model that posits the offsetting components of source confusion (prime features are confused with target features) and discounting (evidence from primed features is discounted). The authors obtained compelling evidence for these components by showing how they can cooperate or compete through different manipulations of prime salience. The model allows for dissociations between prime salience and the magnitude of priming, thereby providing a unified account of "subliminal" and "supraliminal" priming.

Pairs do not suffer interference from other types of pairs or single items in associative recognition

What is the source of interference on a memory test following study of a list containing different types of pairs? Many current models predict that pairs and singles of all types will jointly interfere and therefore harm memory. Such list length effects have often been observed for lists of a single-item type (e.g., a list of words). Here, we examine interference for lists containing multiple types of pairs (e.g., word-word, face-face, word-face). In three experiments, we manipulate the number of each type on the study list. In associative recognition, discrimination fell as the number of pairs of the same type rose, but the number of pairs of other types had little effect. That is, we found a list length effect within, but not between, classes of stimuli. We highlight the importance of representation and propose alternatives to current model representations that can predict such findings.

High-level effects of masking on perceptual identification

The extent to which visual form versus higher-level information is used to identify briefly flashed words is assessed in a perceptual identification task. In this task, a word is briefly flashed, post-masked, and a decision is made between two alternatives. The availability of visual (e.g., case or color) and higher-level information (e.g., abstract letter codes, phonology, and meaning) was manipulated by varying the information that discriminates the alternatives. Performance was better with higher-level than with visual information when pattern post-masks were used, but the reverse occurred without masking. The authors conclude that both higher-level and visual-form information can be used to identify words with the strategy depending on the information available at the time of the choice.

A model for evidence accumulation in the lexical decision task

We present a new model for lexical decision, REM-LD, that is based on REM theory (e.g., ). REM-LD uses a principled (i.e., Bayes' rule) decision process that simultaneously considers the diagnosticity of the evidence for the 'WORD' response and the 'NONWORD' response. The model calculates the odds ratio that the presented stimulus is a word or a nonword by averaging likelihood ratios for lexical entries from a small neighborhood of similar words. We report two experiments that used a signal-to-respond paradigm to obtain information about the time course of lexical processing. Experiment 1 verified the prediction of the model that the frequency of the word stimuli affects performance for nonword stimuli. Experiment 2 was done to study the effects of nonword lexicality, word frequency, and repetition priming and to demonstrate how REM-LD can account for the observed results. We discuss how REM-LD could be extended to account for effects of phonology such as the pseudohomophone effect, and how REM-LD can predict response times in the traditional 'respond-when-ready' paradigm.

Termination of a visual search with large display size effects

The ability to locate an object in the visual field is a collaboration of at least three intermingled processes: scanning multiple locations, recognizing the object sought (the target), and ending the search in cases when the target is not found. In this paper, we focus on the termination rule. Using distribution analyses, it is possible to assess the probability of termination conditional on the number of locations examined. The results show that on some trials without target, the participants carried out more comparisons than there are objects in the display; in other conditions, they carried out fewer comparisons than objects. Because there were very few errors, the premature stops were not pure guesses. We present models to account for these findings. The distributions of terminations help determine the slopes of the functions relating response time to set size.

Context Noise and Item Noise Jointly Determine Recognition Memory: A Comment on Dennis and Humphreys (2001)

S. Dennis and M. S. Humphreys (see record 2001-17194-007) proposed a model with the strict assumption that recognition memory is not affected by interference from other items. Instead, confusions are due to noise generated by prior contexts in which the test item appeared. This model seems disparate from existing models of recognition memory but is similar in many ways that are not superficially obvious. One difference is the order in which item and context information are used as retrieval cues. A more critical difference is the assertion that only an item's history, and not other items, affects recognition memory. Conceptual arguments along with the results of 2 experiments make a persuasive case that both types of noise affect recognition. To illustrate the approach, the authors fit experimental data with a version of the retrieving effectively from memory model (R. M. Shiffrin & M. Steyvers, 1997) incorporating both sources of noise.

Nonword Repetition Priming in Lexical Decision Reverses as a Function of Study Task and Speed Stress

The authors argue that nonword repetition priming in lexical decision is the net result of 2 opposing processes. First, repeating nonwords in the lexical decision task results in the storage of a memory trace containing the interpretation that the letter string is a nonword; retrieval of this trace leads to an increase in performance for repeated nonwords. Second, nonword repetition results in increased familiarity, making the nonword more "wordlike," leading to a decrease in performance. Consistent with this dual-process account, Experiment 1 showed a facilitatory effect for nonwords studied in a lexical decision task but an inhibitory effect for nonwords studied in a letter-height task. Experiment 2 showed inhibitory nonword repetition priming for participants tested under speed-stress instructions.

Turning up the Noise or Turning Down the Volume? On the Nature of the Impairment of Episodic Recognition Memory by Midazolam

E. Hirshman, J. Fisher, T. Henthom, J. Amdt, and A. Passanname (2002) found that Midazolam disrupts the mirror-patterned word-frequency effect for recognition memory by reversing the typical hit-rate advantage for low-frequency words. They noted that this result is consistent with dual-process accounts (e.g., R. C. Atkinson & J. F. Juola, 1974; G. Mandler, 1980; A. P. Yonelinas, 1994) of the word frequency effect for recognition memory (S. Joordens & W. E. Hockley. 2000; L. M. Reder et al. 2000). The present authors show that this finding is also consistent with a variety of single-process, retrieving effectively- from-memory (REM) models (R. M. Shiffrin & M. Steyvers, 1997), the simplest of which assumes that Midazolam decreases the accuracy with which memory traces are stored. These findings therefore do not discriminate between single- and dual-process models of recognition memory.

Semantic context effects and priming in word association

Two experiments investigated priming in word association, an implicit memory task. In the study phase of Experiment 1, semantically ambiguous target words were presented in sentences that biased their interpretation. The appropriate interpretation of the target was either congruent or incongruent with the cue presented in a subsequent word association task. Priming (i.e., a higher proportion of target responses relative to a nonstudied baseline) was obtained for the congruent condition, but not for the incongruent condition. In Experiment 2, study sentences emphasized particular meaning aspects of nonambiguous targets. The word association task showed a higher proportion of target responses for targets studied in the more congruent sentence context than for targets studied in the less congruent sentence context. These results indicate that priming in word association depends largely on the storage of information relating the cue and target.

Auditory registration without learning

In 3 studies, the authors explore how repeated exposure to a spoken word affects memory for perceptual attributes associated with the word (such as a talker's voice or a word's plurality). Subjects heard a list of words; particular words were repeated differing numbers of times. At test, subjects estimated the frequency of each word, with instructions to give frequency judgments of "zero" to words with changed attributes. The experiments demonstrate that memory for perceptual attributes improves very little after the first few repetitions, although word memory continues to improve. The experiments extend the registration without learning effect (D. L. Hintzman, T. Curran, & B. Oppy, 1992) to auditory words, to complex attributes (voice), and to conditions of low and high stimulus variability (two or many voices).

Auditory registration without learning

In 3 studies, the authors explore how repeated exposure to a spoken word affects memory for perceptual attributes associated with the word (such as a talker's voice or a word's plurality). Subjects heard a list of words; particular words were repeated differing numbers of times. At test, subjects estimated the frequency of each word, with instructions to give frequency judgments of "zero" to words with changed attributes. The experiments demonstrate that memory for perceptual attributes improves very little after the first few repetitions, although word memory continues to improve. The experiments extend the registration without learning effect (D. L. Hintzman, T. Curran, & B. Oppy, 1992) to auditory words, to complex attributes (voice), and to conditions of low and high stimulus variability (two or many voices).

Mechanisms of source confusion and discounting in short-term priming 2: effects of prime similarity and target duration

D. E. Huber, R. M. Shiffrin, K. B. Lyle, and K. I. Ruys (2001) tested two-alternative, forced-choice (2-AFC) perceptual identification in a short-term priming task. For repetition priming, passive viewing of primes resulted in a preference to choose repeated words, but actively responding to primes resulted in a preference against choosing repeated words. These results were explained with a computational model, responding optimally with unknown sources of evidence (ROUSE), using the offsetting mechanisms of source confusion and discounting. An analysis of ROUSE revealed conditions under which discounting efficacy should diminish, causing a preference for primed words even with active prime processing. Two new studies confirm 2 such conditions: very short target flash durations and very low similarity between primes and primed choice words. These a priori predictions contrast with the a posteriori data fits of a multinomial model developed by R. Ratcliff and G. McKoon (2001).

Mechanisms of source confusion and discounting in short-term priming: 1. Effects of prime duration and prime recognition

Huber, Shriffrin, Lyle, and Ruys (2001) measured short-term repetition priming effects in perceptual identification with two-alternative forced-choice testing. There was a preference to choose repeated words following passive viewing of primes and a preference against choosing repeated words following active responding to primes. In this present study, we explored conditions of prime processing that produce this pattern of results. Experiment 1 revealed that increased prime duration under passive viewing instructions produces the active priming pattern. Experiment 2 assessed memory for primes: With poor recognition of primes, there was a strong preference for repeated words; however, with good recognition of primes, this preference was eliminated. These results are modeled by a computational theory of optimal decision making, responding optimally with unknown sources of evidence (ROUSE). In ROUSE, a preference for repeated words results from source confusion between primes and choice words. A reversal in the direction of preference arises from the discounting of words known to have also appeared as primes.

Feature frequency effects in recognition memory

Rare words are usually better recognized than common words, a finding in recognition memory known as the word-frequency effect. Some theories predict the word-frequency effect because they assume that rare words consist of more distinctive features than do common words (e.g., Shiffrin & Steyvers's, 1997, REM theory). In this study, recognition memory was tested for words that vary in the commonness of their orthographic features, and we found that recognition was best for words made up of primarily rare letters. In addition, a mirror effect was observed: Words with rare letters had a higher hit rate and a lower false-alarm rate than did words with common letters. We also found that normative word frequency affects recognition independently of letter frequency. Therefore, the distinctiveness of a word's orthographic features is one, but not the only, factor necessary to explain the word-frequency effect.

Perceptual inertia: spatial attention and warning foreperiod?

Perceptual inertia refers to a potential explanation for the observation that during a short period after stimulus onset, the visual system is insensitive to discriminatory detail. The present study attempted to replicate this empirical result in a simple one-item letter-identification task. The results provided little if any support for the construct of perceptual inertia. In the five experiments reported, evidence consistent with perceptual inertia was only obtained in Experiment 5. However, the Experiment 5 results can at least equally parsimoniously be explained in terms of two standard explanatory factors: an effect of precuing of the target position (selective attention) and foreperiod duration (general preparation).