TODAM2: A model for the storage and retrieval of item, associative, and serial-order information.

Presents an extended version of the convolution–correlation memory model TODAM (theory of distributed associative memory) that not only eliminates some of the inadequacies of previous versions but also provides a unified treatment of item, associative, and serial-order information. The chunking model extended the basic convolution–correlation formalism by using multiple convolutions, n-grams (multiple autoassociations of sums of item vectors), and chunks (sums of n-grams) to account for chunking and serial organization. TODAM2 extends the chunking model by including rn-grams (reduced n-grams), labels, and "lebals" (the involution or mirror image of a label) to provide a general model for episodic memory. For paired associates, it is assumed that Ss store only labeled n-grams and lebaled rn-grams. It is shown that the model is broadly consistent with a number of major empirical paired-associate and serial-order effects. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Effects of bilateral eye movements on the retrieval of item, associative, and contextual information.

Two experiments are reported that investigate the effects of saccadic bilateral eye movements on the retrieval of item, associative, and contextual information. Experiment 1 compared the effects of bilateral versus vertical versus no eye movements on tests of item recognition, followed by remember-know responses and associative recognition. Supporting previous research, bilateral eye movements enhanced item recognition by increasing the hit rate and decreasing the false alarm rate. Analysis of remember-know responses indicated that eye movement effects were accompanied by increases in remember responses. The test of associative recognition found that bilateral eye movements increased correct responses to intact pairs and decreased false alarms to rearranged pairs. Experiment 2 assessed the effects of eye movements on the recall of intrinsic (color) and extrinsic (spatial location) context. Bilateral eye movements increased correct recall for both types of context. The results are discussed within the framework of dual-process models of memory and the possible neural underpinnings of these effects are considered. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Time course of item and associative information: Implications for global memory models.

The time course of availability of associative and item information was examined by using a response signal procedure. Associative information discriminates between a studied pair of words and a pair with words from two different studied pairs. Item information is sufficient to discriminate between a studied pair and a pair not studied. In two experiments, discriminations that require associative information are delayed relative to those based on item information. Two additional experiments discount alternative explanations in terms of the time to encode the test items or task strategies. Examination of the global memory models of G. Gilland and R. M. Shiffrin, D. L. Hintzman, and B. B. Murdock (see PA, Vols 71:8340, 76:10832, and 69:4936, respectively) shows that the models treat item and associative information inseparably. Modifications to these models which can produce separate contributions for item and associative information do not predict any difference in their availablility. Two possible mechanisms for the delayed availability of associative information are considered: the involvement of recall in recognition and the time required to form a compound cue. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Effects of aging and prospective memory on recognition of item and associative information.

Older adults typically perform worse than younger adults on tasks of associative, relative to item, memory. One account of this deficit is that older adults have fewer attentional resources to encode associative information. Previous researchers investigating this issue have divided attention at encoding and then have examined whether associative and item recognition were differentially affected. In the current study, we used a different cognitive task shown to tax attentional resources: event-based prospective memory. Although older adults demonstrated worse associative, relative to item, memory, the presence of the prospective memory task at encoding decreased item and associative memory accuracy to the same extent in both age groups. These results do not support the resource account of age-related associative deficits. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Recognition memory ROCs for item and associative information: the contribution of recollection and familiarity

Receiver-operating characteristics (ROCs) were examined in three recognition memory experiments. ROCs for item information (i.e., was this word presented?) were found to be curvilinear. However, ROCs for associative information (i.e., were these two words presented together?) were found to be linear. The results are in agreement with the predictions of a dual-process model that assumes that recognition judgments are based on familiarity and recollection. Familiarity reflects the assessment of a continuous strength dimension and is well described as a signal detection process, whereas recollection reflects the retrieval of qualitative information about the study episode and behaves like a discrete threshold process. The results showed that memory judgments about items relied on a combination of recollection and familiarity, but that judgments about associations relied primarily on recollection. Further examination of the associative ROCs suggested that subjects were able to recollect that old pairs of items were in the study list, and, under some conditions, that new pairs were not in the study list.     

Comparison of the retrieval of item versus spatial position information

It has been argued that temporal and spatial position information are represented similarly, but prior research comparing their time course of retrieval with item information has not supported this conclusion. The time course of retrieval was compared for spatial position and item information in 3 response signal experiments, and differences were found in the time course of retrieval that paralleled those found previously for temporal position and item information (B.M. McElree & B.A. Dosher, 1993). The finding was unaffected by restrictions on the degree of relational support, postretrieval decision difficulty, and the elimination of a strategy favoring item recognition. The authors conclude by discussing whether the data indicate that a recall process was contributing to recognition performance.     

Critique of the retrieval/deblurring assumptions of the theory of distributed associative memory.

Critiques the retrieval assumptions proposed by S. Lewandowsky and B. B. Murdock (see record 1989-14457-001) in their application of Murdock's theory of distributed associative memory (TODAM) to problems in serial-order recall. Two different methods for "deblurring" the products of retrieval are described, along with simulations appropriate for each. It is demonstrated that the deblurring assumptions used by Lewandowsky and Murdock in their simulation version of the model, although appropriate for some aspects of serial-anticipation learning, provide an inadequate account of general serial recall and, in fact, predict several trends that are inconsistent with known data. The analytic version of the model is considered and some additional problems are noted. Overall, the deblurring assumptions critically affect the performance of TODAM, and it is these assumptions rather than the model per se that determine a sizable proportion of its behavior. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Storage and retrieval of associative clusters: A stages-of-learning analysis of associative memory traces.

In this research, the assumptions underlying the unitary trace theory of item representation and acquisition were tested in two cued-recall experiments in which the degree of preexperimental knowledge (typicality) was manipulated. Subjects learned lists of word triads (each of which consisted of a single cue and two targets) to a stringent acquisition criterion. In Experiment 1, typicality was manipulated in the absence of semantic relationships between members of the associative clusters. In Experiment 2, semantic relationships were present among cluster members, and preexperimental knowledge was manipulated by varying the degree of intracluster category membership as measured by whether cue and target items were typical or atypical category exemplars. In both experiments a mathematical model that embodies stages-of-learning distinctions was used to analyze the acquisition data. The results indicated that (1) cues and targets were represented in a single holistic memory trace, and (2) the manipulation of the degree of preexperimental knowledge affected both trace storage and retrieval learning, but had only a minimal impact on retrieval performance between the time a trace was stored and the time retrieval learning was complete. It was argued that these findings are consistent with a single unitary trace interpretation, namely, the modified storage-retrieval model. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

A nonlinear mixed model framework for item response theory.

Mixed models take the dependency between observations based on the same cluster into account by introducing 1 or more random effects. Common item response theory (IRT) models introduce latent person variables to model the dependence between responses of the same participant. Assuming a distribution for the latent variables, these IRT models are formally equivalent with nonlinear mixed models. It is shown how a variety of IRT models can be formulated as particular instances of nonlinear mixed models. The unifying framework offers the advantage that relations between different IRT models become explicit and that it is rather straightforward to see how existing IRT models can be adapted and extended. The approach is illustrated with a self-report study on anger. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Effects of aging and IQ on item and associative memory.

The effects of aging and IQ on performance were examined in 4 memory tasks: item recognition, associative recognition, cued recall, and free recall. For item and associative recognition, accuracy and the response time (RT) distributions for correct and error responses were explained by Ratcliff's (1978) diffusion model at the level of individual participants. The values of the components of processing identified by the model for the recognition tasks, as well as accuracy for cued and free recall, were compared across levels of IQ (ranging from 85 to 140) and age (college age, 60–74 years old, and 75–90 years old). IQ had large effects on drift rate in recognition and recall performance, except for the oldest participants with some measures near floor. Drift rates in the recognition tasks, accuracy in recall, and IQ all correlated strongly. However, there was a small decline in drift rates for item recognition and a large decline for associative recognition and cued recall accuracy (70%). In contrast, there were large effects of age on boundary separation and nondecision time (which correlated across tasks) but small effects of IQ. The implications of these results for single- and dual-process models of item recognition are discussed, and it is concluded that models that deal with both RTs and accuracy are subject to many more constraints than are models that deal with only one of these measures. Overall, the results of the study show a complicated but interpretable pattern of interactions that present important targets for modeling. (PsycINFO Database Record (c) 2011 APA, all rights reserved)     

Differential effects of age on item and associative measures of memory: A meta-analysis.

In this meta-analysis, the authors evaluated recent suggestions that older adults' episodic memory impairments are partially due to a reduced ability to encode and retrieve associated/bound units of information. Results of 90 studies of episodic memory for both item and associative information in 3,197 young and 3,192 older adults provided support for the age-related associative/binding deficit suggestion, indicating a larger effect of age on memory for associative information than for item information. Moderators assessed included the type of associations, encoding instructions, materials, and test format. Results indicated an age-related associative deficit in memory for source, context, temporal order, spatial location, and item pairings, in both verbal and nonverbal material. An age-related associative deficit was quite pronounced under intentional learning instructions but was not clearly evident under incidental learning instructions. Finally, test format was also found to moderate the associative deficit, with older adults showing an associative/binding deficit when item memory was evaluated via recognition tests but not when item memory was evaluated via recall tests, in which case the age-related deficits were similar for item and associative information. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

A neural system analysis of memory storage and retrieval.

Contends that from an information-processing viewpoint, memory can be subdivided into cue-access, short-term memory, and long-term memory storage and retrieval systems, which in turn are controlled by a number of operations, (e.g., match-mismatch, decay, and selective attention). Furthermore, it is assumed that specific neural substrates are maximally involved in the modulation of these specific processes essential to efficient mnemonic processing of information. Evidence is presented from previous studies to support this theoretical view of information processing. This evidence suggests that (a) the sensory systems and the cerebral cortex are critically involved in match-mismatch processing of information in the cue-access system, (b) the midbrain reticular formation and association cortex process information in the short-term memory system, and (c) the hippocampus is critically involved in consolidation and read-out of information in the long-term memory system. Evidence is also presented to suggest that after an initial preperceptual analysis information is transferred in parallel to the short-term and long-term memory systems, but that superimposed upon this parallel structure are sequential transfer processes (e.g., rehearsal). (6 p. ref.) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Age differences in memory for item and source information.

Investigated the effects of normal aging on source amnesia in 2 experiments. In Exp I, 31 young adults (mean age 19.4 yrs) and 30 older adults (mean age 69.2 yrs) were taught real facts about Canada. One week later they were asked to recall the facts and remember where they had learned them. Findings show that the older people exhibited greater amounts of forgetting of the source of their knowledge. Exp II, which used 24 young adults (mean age 23.3 yrs) and 24 older adults (mean age 69.7 yrs), confirmed the findings of Exp I using made up facts. It is suggested that the finding of source amnesia in older, normal people has implications for theories of amnesia and, possibly, for theories of frontal lobe functions. (French abstract) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Generalized linear item response theory.

Generalized linear item response theory is discussed, which is based on the following assumptions: (1) A distribution of the response occurs according to given item format; (2) the item responses are explained by 1 continuous or nominal latent variable and p latent as well as observed variables that are continuous or nominal; (3) the responses to the different items of a test are independently distributed given the values of the explanatory variables; and (4) a monotone differentiable function g of the expected item response τ is needed such that a linear combination of the explanatory variables is a predictor of g(τ). It is shown that most of the well-known psychometric models are special cases of the generalized theory and that concepts such as differential item functioning, specific objectivity, reliability, and information can be subsumed under the generalized theory. (PsycINFO Database Record (c) 2011 APA, all rights reserved)     

A multisample item response theory analysis of the Beck Depression Inventory-1A.

The widespread employment of the Beck Depression Inventory-1A ({bdi}-1{a}) has spawned a number of practices: (1) The employment of an unweighted total score as a measure of depression; (2) Its use in populations other than that in which it was normed; and (3) The employment of {bdi}-1{a} total scores in hypothesis tests about population differences in mean depression. A sequential procedure based on item response theory was employed to assess the validity of these practices for the case of 4 populations: clinical depressives (n?=?210), mixed nondepressed psychiatric patients (n?=?98), and students from 2 different universities (n?=?624). The findings suggest that the 1st practice was not justified for any of these populations, that the {bdi}-1{a} was employable only with clinical depressives and with 1 of the university populations, and that mean comparisons were not allowable. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Evaluation of two methods for estimating item response theory parameters when assessing differential item functioning.

Recent legal developments appear to sanction the use of psychometrically unsound procedures for examining differential item functioning (DIF) on standardized tests. More appropriate approaches involve the use of item response theory (IRT). However, many IRT-based DIF studies have used F. M. Lord's (see record 1987-17535-001) joint maximum likelihood procedure, which can lead to incorrect and misleading results. A Monte Carlo simulation was conducted to evaluate the effectiveness of two other methods of parameter estimation: marginal maximum likelihood estimation and Bayes modal estimation. Sample size and data dimensionality were manipulated in the simulation. Results indicated that both estimation methods (a) provided more accurate parameter estimates and less inflated Type I error rates than joint maximum likelihood, (b) were robust to multidimensionality, and (c) produced more accurate parameter estimates and higher rates of identifying DIF with larger samples. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Data analysis using item response theory.

The purpose of this article is to illustrate the power of item response theory (IRT) for the item analysis of measurement instruments in psychology. Through illustration, we show that IRT latent variable models fit data from a wide variety of sources and that interpretation of the features of these fitted models leads to interesting insights into the psychology underlying the data. The illustrations involve personality and attitude measurement as well as the evaluation of cognitive proficiency. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

The effects of age in four alternative forced-choice item and associative recognition tasks.

Seventy-three young and 84 older adults were taught interactive imagery as a strategy for learning word pairs. In the control condition, participants viewed word pairs 1 at a time and formed an interactive image for each. In the experimental condition, participants first formed individual mental images for both the cue and the target and then formed an interactive image for the pair. Participants in both conditions then completed 4 alternative forced-choice item and associative recognition tasks that avoid influences of age differences in retrieval strategies such as recall-to-reject. Unlike findings with typical yes–no recognition tests, associative recognition was superior to item recognition in the control condition. This effect was attenuated in the experimental condition. Older adults had poorer recognition memory for both associative and item tests, with a larger age difference for recognizing new associations. (PsycINFO Database Record (c) 2010 APA, all rights reserved)