Amy H. Criss

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 items 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.

On the interpretation of removable interactions: A survey of the field 33 years after Loftus

In a classic 1978 Memory &Cognition article, Geoff Loftus explained why noncrossover interactions are removable. These removable interactions are tied to the scale of measurement for the dependent variable and therefore do not allow unambiguous conclusions about latent psychological processes. In the present article, we present concrete examples of how this insight helps prevent experimental psychologists from drawing incorrect conclusions about the effects of forgetting and aging. In addition, we extend the Loftus classification scheme for interactions to include those on the cusp between removable and nonremovable. Finally, we use various methods (i.e., a study of citation histories, a questionnaire for psychology students and faculty members, an analysis of statistical textbooks, and a review of articles published in the 2008 issue of Psychology andAging) to show that experimental psychologists have remained generally unaware of the concept of removable interactions. We conclude that there is more to interactions in a 2 × 2 design than meets the eye.

Differentiation and Response Bias in Episodic Memory: Evidence From Reaction Time Distributions

In differentiation models, the processes of encoding and retrieval produce an increase in the distribution of memory strength for targets and a decrease in the distribution of memory strength for foils as the amount of encoding increases. This produces an increase in the hit rate and decrease in the false-alarm rate for a strongly encoded compared with a weakly encoded list, consistent with empirical data. Other models assume that the foil distribution is unaffected by encoding manipulations or the foil distribution increases as a function of target strength. They account for the empirical data by adopting a stricter criterion for strongly encoded lists relative to weakly encoded lists. The differentiation and criterion shift explanations have been difficult to discriminate with accuracy measures alone. In this article, reaction time distributions and accuracy measures are collected in a list-strength paradigm and in a response bias paradigm in which the proportion of test items that are targets is manipulated. Diffusion model analyses showed that encoding strength is primarily accounted for by changes in the rate of accumulation of evidence (i.e., drift rate) for both targets and foils and manipulating the proportion of targets is primarily accounted for by changes in response bias (i.e., starting point). The diffusion model analyses is interpreted in terms of predictions of the differentiation models in which subjective memory strength is mapped directly onto drift rate and criterion placement is mapped onto starting point. Criterion shift models require at least 2 types of shifts to account for these findings.

The distribution of subjective memory strength: list strength and response bias.

Models of recognition memory assume that memory decisions are based partially on the subjective strength of the test item. Models agree that the subjective strength of targets increases with additional time for encoding however the origin of the subjective strength of foils remains disputed. Under the fixed strength assumption the distribution of memory strength for foils is invariant across experimental manipulations of encoding. For example, the subjective strength of foils may depend solely on the pre-experimental history of the item, thus encoding manipulations have no impact. In contrast, under the differentiation assumption the subjective strength of foils depends on the nature of the traces stored in episodic memory. If those traces are well encoded, the subjective strength of foils will be lower than the case where noisy traces are stored (e.g., when targets received minimal encoding). The fixed strength and differentiation accounts are tested by measuring direct ratings of memory strength. In Experiments 1 and 2, item strength is varied via repetition and in Experiment 3 response bias is varied via the relative proportion of targets on the test list. For all experiments empirical distributions of memory strength were obtained and compared to the distributions predicted by the two accounts. The differentiation assumption provides the most parsimonious account of the data.

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.

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.

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.

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.

A differentiation account of recognition memory: Evidence from fmri

Differentiation models of recognition memory predict a strength-based mirror effect in the distributions of subjective memory strength. Subjective memory strength should increase for targets and simultaneously decrease for foils following a strongly encoded list compared with a weakly encoded list. An alternative explanation for the strength-based mirror effect is that participants adopt a stricter criterion following a strong list than a weak list. Behavioral experiments support the differentiation account. The purpose of this study was to identify the neural bases for these differences. Encoding strength was manipulated (strong, weak) in a rapid event-related fMRI paradigm. To investigate the effect of retrieval context on foils, foils were presented in test blocks containing strong or weak targets. Imaging analyses identified regions in which activity increased faster for foils tested after a strong list than a weak list. The results are interpreted in support of a differentiation account of memory and are suggestive that the angular gyrus plays a role in evaluating evidence related to the memory decision, even for new items.

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.