Priming in implicit memory tasks: Prior study causes enhanced dicriminality, not only bias.

R. Ratcliff and G. McKoon (1995, 1996, 1997; R. Ratcliff, D. Allbritton, & G. McKoon, 1997) have argued that repetition priming effects are solely due to bias. They showed that prior study of the target resulted in a benefit in a later implicit memory task. However, prior study of a stimulus similar to the target resulted in a cost. The present study, using a 2-alternative forced-choice procedure, investigated the effect of prior study in an unbiased condition: Both alternatives were studied prior to their presentation in an implicit memory task. Contrary to a pure bias interpretation of priming, consistent evidence was obtained in 3 implicit memory tasks (word fragment completion, auditory word identification, and picture identification) that performance was better when both alternatives were studied than when neither alternative was studied. These results show that prior study results in enhanced discriminability, not only bias. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Commonalities and differences in the working memory components underlying letter and category fluency tasks: A dual-task investigation.

This study used a dual-task interference paradigm to test the hypothesis that different subcomponents of working memory differentially contribute to performance on letter fluency and category fluency tasks. College students (N = 96) performed each type of verbal fluency task in isolation and concurrently with I of 3 secondary tasks. The secondary tasks were chosen for their putative involvement in different working memory subcomponents. Two subsystems of working memory, the phonological loop and the visuospatial sketchpad, were identified as important contributors to fluency performance, especially to performance on letter fluency and category fluency tasks, respectively. Moreover, the results also suggest that the executive function, mental set shifting, may be deployed to perform both letter fluency and category fluency tasks. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Response biases in the MMPI: A sequential analysis.

Conceptions of "response bias" have figured prominently in two dissimilar research areas, psychophysical tasks and assessment techniques. These areas share a common methodological problem—how to assess the contribution of non-content-determined sequential dependencies. A general technique is presented for assessing sequential dependencies in MMPI responses, and in responses to an instructional set to be random in a non-content guessing task. For MMPI responses, the effect of item content clearly overrides any tendency to develop sequential dependencies; response bias is limited to total number of True or False responses. In non-content guessing tasks, sequential dependencies play a major role. This general technique for measuring such biases provides a unifying conceptualization of non-content-determined response patterning. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Human hippocampal activation in the delayed matching-and nonmatching-to-sample memory tasks: An event-related functional MRI approach.

The delayed matching-to-sample (DMS) and delayed nonmatching-to-sample (DNMS) memory tasks are standard tools used to probe visual recognition memory in human and nonhuman primates. Previous research indicates that structures within the medial temporal lobe, including the hippocampus, make up a crucial memory circuit for successful performance on these tasks. In the present investigation, event-related functional magnetic resonance imaging was used to examine activation in the hippocampus proper during these memory tasks relative to a perceptuomotor task involving the same stimuli. The results indicate that both memory tasks elicited greater activation in the right hippocampus during the encoding phase. These findings are consistent with the work from human patients and animal studies, indicating hippocampal involvement in the DMS and DNMS tasks. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Sex differences in social memory tasks.

College females were superior to college males in memory for 3 tasks—one life situation and 2 names-and-faces tests. A new test, the KW Memory for Names and Faces Test, demonstrated a "same-sex recall" tendency for this sample. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Complex span versus updating tasks of working memory: The gap is not that deep.

How to best measure working memory capacity is an issue of ongoing debate. Besides established complex span tasks, which combine short-term memory demands with generally unrelated secondary tasks, there exists a set of paradigms characterized by continuous and simultaneous updating of several items in working memory, such as the n-back, memory updating, or alpha span tasks. With a latent variable analysis (N = 96) based on content-heterogeneous operationalizations of both task families, the authors found a latent correlation between a complex span factor and an updating factor that was not statistically different from unity (r = .96). Moreover, both factors predicted fluid intelligence (reasoning) equally well. The authors conclude that updating tasks measure working memory equally well as complex span tasks. Processes involved in building, maintaining, and updating arbitrary bindings may constitute the common working memory ability underlying performance on reasoning, complex span, and updating tasks. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Age differences in repeated learning tasks in schizophrenic subjects.

This experiment was designed to study age differences in the learning of paired associates in serial order and a card-sorting task over 9 different sessions. The Ss consisted of 2 groups, 15 younger-aged (20-29) and 15 middle-aged (40-56), male, hospitalized schizophrenics. The results indicated that the younger-aged-group's performance was superior on both tasks for the 1st session. Over the 9 learning sessions the middle-aged group showed significantly greater improvement on the paired-associate task, while the differences between the age groups in card-sorting speed remained fairly constant over the 9 sessions. It was concluded that the learning deficit in middle-aged and schizophrenic Ss is something that is not a fixed and immutable one for all tasks but may be modified through practice. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

A test of hue memory.

A hue memory test consisting of 20 chips from the Farnsworth-Munsell hue series (S is required to select a same-hued chip after brief exposure of each test chip) was developed. Test-retest reliabilities for two groups were .68 and .59. Item data and correlations with the Woods Color Aptitude Test and the ISCC CAT are presented. "Neither the present test nor Woods' test is a valid substitute for the ISCC CAT… . By itself, the present test is certainly valid as a test of hue memory since it is a direct test of immediate memory for hue dissociated from the factor of configuration." (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Chunk Limits and Length Limits in Immediate Recall: A Reconciliation.

Whereas some research on immediate recall of verbal lists has suggested that it is limited by the number of chunks that can be recalled (e.g., N. Cowan, Z. Chen, & J. N. Rouder, 2004; E. Tulving & J. E. Patkau, 1962), other research has suggested that it is limited by the length of the material to be recalled (e.g., A. D. Baddeley, N. Thomson, & M. Buchanan, 1975). The authors investigated this question by teaching new paired associations between words to create 2-word chunks. The results suggest that both chunk capacity limits and length limits come into play. For the free recall of 12-word lists, 6 pre-learned pairs could be recalled about as well as 6 pre-exposed singletons, suggesting a chunk limit. However, for the serially ordered recall of 8-word lists, 4 pre-learned pairs could be recalled about as well as 8 pre-exposed singletons, suggesting a length limit. Other conditions yielded intermediate results suggesting that sometimes both limits may operate together. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Assessing the age-related effects of proactive interference on working memory tasks using the Rasch model.

Inhibition-reduction theory (L. Hasher & R. Zacks, 1988) hypothesizes that the age-related decline in working memory (WM) span is a result of a decrease in the ability to inhibit irrelevant information in WM. Using the Rasch psychometric model, this study found that later trials on 2 WM span tasks were more difficult for older adults than for younger adults, consistent with inhibition-reduction theory's hypothesis that older adults are more susceptible to the effects of proactive interference (PI). Furthermore, after accounting for differential susceptibility to the effects of PI, age-related variance in WM span was reduced by about half. These results suggest that differential susceptibility to PI may account for a substantial portion, although not all, of the age-related decline in WM span. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Orienting attention in visual working memory reduces interference from memory probes.

Given a changing visual environment, and the limited capacity of visual working memory (VWM), the contents of VWM must be in constant flux. Using a change detection task, the authors show that VWM is subject to obligatory updating in the face of new information. Change detection performance is enhanced when the item that may change is retrospectively cued 1 s after memory encoding and 0.5 s before testing. The retro-cue benefit cannot be explained by memory decay or by a reduction in interference from other items held in VWM. Rather, orienting attention to a single memory item makes VWM more resistant to interference from the test probe. The authors conclude that the content of VWM is volatile unless it receives focused attention, and that the standard change detection task underestimates VWM capacity. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Working memory for complex figures: An fMRI comparison of letter and fractal n-back tasks.

n-back letter and fractal tasks were administered to I I participants during functional magnetic resonance imaging to test process specificity theories of prefrontal cortex (PFC) function and assess task validity. Tasks were matched on accuracy, but fractal n-back responses were slower and more conservative. Maintenance (1-back minus O-back) activated inferior parietal and dorsolateral PFC, with additional activation in right ventrolateral PFC during letter n-back and left lingual gyrus during fractal n-back. Maintenance plus manipulation (2-back minus 0-back) activated inferior parietal, Broca's area, insula, and dorsolateral and ventral PFC, with greater right dorsolateral PFC activation for letter n-back. Manipulation only (2-back minus 1-back) produced additional and equivalent dorsolateral PFC and anterior cingulate activation in both tasks. Results support fractal n-back validity and indicate substantial overlap in working memory functions of dorsal and ventral PFC. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Role of memory in concept learning.

Studies manipulating variables in the attempt to produce different memory requirements in concept learning are reviewed. Many of them have tested Underwood's theoretical position of response contiguity. Performance is generally improved by increasing the availability of previous stimulus information. The degree to which instances of the same concept occur contiguously directly affects acquisition of the concept. Attempts to demonstrate inferior performance with spaced practice have not been successful, although procedural problems make any conclusion tentative. There is some suggestion that memory effects could be classified as proactive and retroactive inhibition. A basic problem concerns the indirect type of question posed by investigators. (36 ref.) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

On the division of short-term and working memory: An examination of simple and complex span and their relation to higher order abilities.

Research has suggested that short-term memory and working memory (as measured by simple and complex span tasks, respectively) are separate constructs that are differentially related to higher order cognitive abilities. This claim is critically evaluated by reviewing research that has compared simple and complex span tasks in both experimental and correlational studies. In addition, a meta-analysis and re-analyses of key data sets were conducted. The review and analyses suggest that simple and complex span tasks largely measure the same basic subcomponent processes (e.g., rehearsal, maintenance, updating, controlled search) but differ in the extent to which these processes operate in a particular task. These differences largely depend on the extent to which phonological processes are maximized and variability from long list lengths is present. Potential methodological, psychometric, and assessment implications are discussed and a theoretical account of the data is proposed. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Cortisol variation in humans affects memory for emotionally laden and neutral information.

In a test of the effects of cortisol on emotional memory, 90 men were orally administered placebo or 20 or 40 mg cortisol and presented with emotionally arousing and neutral stimuli. On memory tests administered within 1 hr of stimulus presentation, cortisol elevations caused a reduction in the number of errors committed on free-recall tasks. Two evenings later, when cortisol levels were no longer manipulated, inverted-U quadratic trends were found for recognition memory tasks, reflecting memory facilitation in the 20-mg group for both negative and neutral information. Results suggest that the effects of cortisol on memory do not differ substantially for emotional and neutral information. The study provides evidence of beneficial effects of acute cortisol elevations on explicit memory in humans. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

The contributions of primary and secondary memory to working memory capacity: An individual differences analysis of immediate free recall.

The present study tested the dual-component model of working memory capacity (WMC) by examining estimates of primary memory and secondary memory from an immediate free recall task. Participants completed multiple measures of WMC and general intellectual ability as well as multiple trials of an immediate free recall task. It was demonstrated that there are 2 sources of variance (primary memory and secondary memory) in immediate free recall and that, further, these 2 sources of variance accounted for independent variation in WMC. Together, these results are consistent with a dual-component model of WMC reflecting individual differences in maintenance in primary memory and in retrieval from secondary memory. Theoretical implications for working memory and dual-component models of free recall are discussed. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Time and cognitive load in working memory.

According to the time-based resource-sharing model (P. Barrouillet, S. Bernardin, & V. Camos, 2004), the cognitive load a given task involves is a function of the proportion of time during which it captures attention, thus impeding other attention-demanding processes. Accordingly, the present study demonstrates that the disruptive effect on concurrent maintenance of memory retrievals and response selections increases with their duration. Moreover, the effect on recall performance of concurrent activities does not go beyond their duration insofar as the processes are attention demanding. Finally, these effects are not modality specific, as spatial processing was found to disrupt verbal maintenance. These results suggest a sequential and time-based function of working memory in which processing and storage rely on a single and general purpose attentional resource needed to run executive processes devoted to constructing, maintaining, and modifying ephemeral representations. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

An investigation of unilateral cerebral pathology with equated verbal and visual-spatial tasks.

Ss with left cerebral damage perform significantly different on certain tasks so as to be distinguishable from Ss with right cerebral damage. In this instance, verbal and visual-spatial paired associations were learned. The results indicated that control Ss (no known cerebral damage) showed no difference on either task, but patients with right cerebral damage (R) did significantly poorer on visual-spatial learning than verbal learning; patients with left cerebral damage (L) did just the reverse. Percent of accuracy of diagnosis of Rs as R, and Ls as L was marred by the factor of age. Measures of perseveration were less clearcut than error scores. From Psyc Abstracts 36:04:4JG82S. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Considerations in the analysis of group tasks.

The transition of research in the area of small-group behavior from survey techniques to the more precise laboratory investigations has resulted in a shift in emphasis to group processes and a relative disinterest in analyzing the tasks which govern behavior. "The major purpose of the present report is to propose a paradigm that may be useful in preliminary attempts to isolate and define important group-task characteristics." (PsycINFO Database Record (c) 2010 APA, all rights reserved)