SEARCH · PubMed Health

Results for “Memory”

Explore indexed PubMed citations for clinical trials, systematic reviews and public health research. Read source abstracts and follow each citation to its original PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 793 records · Page 44Linked to original sources

PubMed1999

Memory for pitch versus memory for loudness.

The decays of pitch traces and loudness traces in short-term auditory memory were compared in forced-choice discrimination experiments. The two stimuli presented on each trial were separated by a variable delay (D); they consisted of pure tones, series of resolved harmonics, or series of unresolved harmonics mixed with lowpass noise. A roving procedure was employed in order to minimize the influence of context coding. During an initial phase of each experiment, frequency and intensity discrimination thresholds [P(C) = 0.80] were measured with an adaptive staircase method while D was fixed at 0.5 s. The corresponding physical differences (in cents or dB) were then constantly presented at four values of D: 0.5, 2, 5, and 10 s. In the case of intensity discrimination, performance (d') markedly decreased when D increased from 0.5 to 2 s, but was not further reduced when D was longer. In the case of frequency discrimination, the decline of performance as a function of D was significantly less abrupt. This divergence suggests that pitch and loudness are processed in separate modules of auditory memory.

Humans↗

PubMed2003

Cardiac memory and cortical memory: do learning patterns in neural networks impact on cardiac arrhythmias?

Memory is a property of diverse biological systems, including brain and heart. Studies in cortical neuronal networks have identified an increased sensitivity to infrequent (rare) stimulation patterns that can result in their achieving dominance over network firing. This adaptive behavior is applied to the heart in an attempt to explain the ability of pulmonary venous and other ectopic foci to achieve dominance over cardiac rhythm. Developmental changes in determinants of cardiac rhythm are explored as possible determinants of the range of rhythms expressed by the heart. By understanding the mechanisms for these behavior patterns, we may obtain new means for manipulating memory to return dysrhythmic hearts to normal sinus rhythm.

Adaptation, Physiological↗

PubMed2006

Dorsolateral prefrontal cortex promotes long-term memory formation through its role in working memory organization.

Results from neuroimaging studies have shown that the dorsolateral prefrontal cortex (DLPFC) implements processes critical for organizing items in working memory (WM). Based on its role in WM, we hypothesized that the DLPFC should contribute to long-term memory (LTM) formation by strengthening associations among items that are organized in WM. We conducted an event-related functional magnetic resonance imaging (fMRI) study to test this hypothesis by investigating prefrontal activity during performance of two different WM tasks: on "rehearse" trials, participants actively maintained triplets of words during a brief delay, whereas on "reorder" trials, participants actively organized each triplet during the delay. After scanning, subjects performed an LTM test on words presented during both WM conditions. Behavioral results showed that WM processing in the reorder condition enhanced LTM by strengthening inter-item associations. fMRI results showed that DLPFC activity specifically during reorder trials was predictive of subsequent LTM. In contrast, activity in the posterior ventrolateral prefrontal cortex was predictive of LTM for words studied on both reorder and rehearse trials. These results support the view that the DLPFC contributes to LTM formation through its role in organization of information in WM.

Adult↗

PubMed1980

Memory deficits in depression: evidence utilizing the Wechsler Memory Scale.

The performance of 21 hospitalized depressed patients was compared to a matched group of 21 controls on the Wechaler Memory Scale. The depressed patients showed deficits on Mental Control, Verbal Learning, and Visual Reproduction tasks, which indicate impairment of memory functions in depression. There may be a deficit in the attention and alerting mechanism of depressed patients.

Adult↗

PubMed1981

Simulation of a memory deficit on the Continuous Recognition Memory Test.

Simulation of a memory deficit on the Continuous Recognition Memory Test was studied, with 20 male and 20 female normal undergraduates assigned to each of two conditions. Simulation with prior test experience was studied by comparing performance following standard and then simulation instructions. A significant increase in false alarms was associated with a significant decrease in correct responses, d', c, and a slight decrease in hits. For studying simulation without prior test experience, the test was administered once with instructions to simulate. Performance was similar to simulation with test experience. Comparisons with the performance of closed head-injured patients were made.

Adult↗

PubMed2001

Possible artifacts in memory assessment with the Wechsler Memory Scale-III.

The Wechsler Memory Scale-III has a number of subtests on which scores can be influenced by random answering, malingering, and response sets as well as valid variance from memory functioning. Clinicians, researchers, and forensic psychologists need to take these possibly confounding sources into account when interpreting findings. Chance performance guidelines are presented along with some brief examples from clinical assessment.

Adult↗

PubMed1991

The relationship between intelligence and memory following minor or mild closed head injury: greater impairment in memory than intelligence.

This study investigated the performance of patients with minor or mild closed head injury and age/education-matched normal controls on the Wechsler Adult Intelligence Scale-Revised (WAIS-R) and the Wechsler Memory Scale-Revised (WMS-R). The results demonstrated that the control group had significantly higher scores than the patients with closed head injury on all WAIS-R and WMS-R index scores. Further analysis revealed that the patients with closed head injury showed a greater impairment in delayed memory when directly compared to intellectual performance that was not seen in the control group. These results are discussed in relation to findings in patients with more severe closed head injury, the construction of the WAIS-R and the WMS-R, and the performance patterns of the two groups.

Adult↗

PubMed2006

Ripple effects in memory: judgments of moral blame can distort memory for events.

Can judging an individual as being morally responsible for a negative act affect memory for details of the act? We presented participants with a story describing an individual (Frank) who committed a crime (he walked out on a restaurant bill). Some participants were told that the negative act was not intentional and that Frank was essentially a good person. Others were told that the negative act was intentional and that Frank actually enjoyed it. Control participants were given no extra information. All the participants then judged Frank's moral responsibility for walking out on the bill. When asked a week later to recall information about the event, the participants who had received negative information about Frank remembered that Frank had walked out on a larger restaurant bill than he actually had. Moreover, the degree of memory distortion was predicted by the degree of moral blame that had been attributed to Frank.

Guilt↗

PubMed2003

Roles of working memory capacity and long-term working memory skill in complex task performance.

In the present research, we examined the relative roles of domain-general and domain-specific individual difference characteristics in complex cognitive task performance. Specifically, we examined the impact both of working memory (WM) capacity and of acquired skills used to encode presented information in an accessible form in long-term working memory (LTWM) on performance in a complex aviation task environment. Measures of WM capacity and LTWM skill served as performance predictors. A criterion measure of task performance was related to the predictor measures. The results indicated that an increase in LTWM skill decreases the role of WM capacity as the determinant of complex task performance, although both measures are important performance predictors. We discuss how the two distinct WM constructs coexist and interact to support complex task performance.

Cognition↗

PubMed2002

Immediate and delayed memory tasks: a computerized behavioral measure of memory, attention, and impulsivity.

The Immediate and Delayed Memory Task (IMT/DMT), a variant of the Continuous Performance Test (CPT), is a new software package designed to be a flexible research tool for the study of attention, memory, and impulsivity. This package allows researchers to determine the design to be used during a testing session and to manipulate many of the parameters. It features two components: the IMT and the DMT, both of which present sequential 2- to 7-digit stimuli with variable presentation rates and intertrial intervals. Subjects respond to identically matched stimuli presented consecutively, spanning a brief period of time (IMT), or to stimuli spanning a greater period of time (during which intervening stimuli to be ignored appear; DMT). Task complexity can be adjusted to suit applications for both children and adults. Preliminary studies have demonstrated that these laboratory tasks are sensitive to group differences, produce stable baselines of performance, and are sensitive to drug-induced performance decrements.

Attention↗

PubMed2004

False memories for compound words: role of working memory.

Subjects studied pairs of compound words; pair members were presented simultaneously (one above the other) for 2 sec or sequentially (one immediately following the other) for 1 sec each, and 6-sec interstimulus intervals separated the end of presentation of one pair and the start of that of another. A subsequent recognition test included within-pair and between-pair conjunction foils (recombinations of stimulus parts from the same study pair and from separate pairs, respectively). Previous experiments using faces as stimuli have demonstrated that when faces are presented simultaneously there are many more false alarms to within-pair than to between-pair conjunction items, and when faces are presented sequentially there is an equal number of false alarms in those two conditions. However, Experiment 1 showed that for compound word stimuli there were equally high false alarm rates toboth types of foils in both study conditions relative to completely new test items. Experiment 2 showed that when rehearsal of compound words was prevented, the pattern of conjunction errors was very similar to the one typically obtained for faces. In Experiment 3, subjects falsely recalled conjunctions of within-pair compound words but not conjunctions of between-pair words in the simultaneous-study condition; no conjunctions were recalled in the sequential-study condition. The results support the idea that working memory processing is necessary for binding stimulus parts together in episodic memory.

Humans↗

PubMed2004

Strong memories obscure weak memories in associative recognition.

The list strength effect, in which strengthening some memories has a detrimental effect on the retrieval of other memories, has generally not been found in item recognition. The present study shows that the list strength effect does occur in associative recognition. Study materials were sets of overlapping word pairs (A-B, A-C, D-B, etc.). Within critical sets of words, strong pairs were presented three times at study, as compared with one presentation for weak pairs. In Experiment 1, associative recognition for weak pairs was less accurate than that for baseline pairs, and response times for hits were slower. In Experiment 2, receiver-operating characteristic curve data provided further evidence of poor accuracy for weak pairs. These findings support a qualitative distinction between item and associative recognition.

Association↗

PubMed2004

Memory for targets in a multilevel simulated environment: evidence for vertical asymmetry in spatial memory.

In two experiments, adult participants explored a symmetrical three-tiered computer-simulated building that contained six distinctive objects, two on each floor. Following exploration, the objects were removed, and the participants were asked to make direction judgments from each floor, indicating the former positions of the objects on that floor and on higher and lower floors. Relative tilt error scores indicated a bias, in that targets that were higher than the test location were judged as consistently lower than their actual positions and targets that were lower than the test location were judged as consistently higher than their actual positions. Absolute tilt errors revealed an asymmetry, with more accurate and less variable tilt errors for judgments directed to lower floors than for judgments directed to higher floors. Experiment 3 ruled out an account of the findings that does not relate them to spatial memory. The results suggest that the superiority of downward over upward spatial judgments, previously reported in two-dimensional visual-spatial tasks, extends to navigational spatial memory.

Adolescent↗

PubMed1992

Memory-conjunction errors: miscombination of stored stimulus features can produce illusions of memory.

We demonstrate that subjects will often claim to have previously seen a new stimulus if they have previously seen stimuli containing its component features. Memory for studied stimuli was measured using a "yes"/"no" recognition test. There were three types of test stimuli: target stimuli, which had been presented during study, conjunction stimuli, constructed by combining the features of separate study stimuli, and feature stimuli, in which studied stimulus features were combined with new, unstudied, features. For both nonsense words and faces, the subjects made many more false alarms for conjunction than for feature stimuli. Additional experiments demonstrated that the results were not due to physical similarity between study and test stimuli and that conjunction errors were much more common than feature errors in recall. The results demonstrate that features of stored stimuli maintain some independence in memory and can be incorrectly combined to produce recognition errors.

Humans↗

PubMed2000

The quality of false memory over time: is memory for misinformation "remembered" or "known"?

The conscious quality of eyewitness memory for misinformation after different retention intervals was investigated in two experiments. Participants viewed computer-projected slides depicting a crime (encoding phase), read a narrative containing misinformation, and took a recall test about the original event. Remember/know judgments were made for each response. A "remember" judgment indicated that the participant vividly recalled seeing a detail in the encoding phase. A "know" judgment indicated that the participant believed that a detail was presented but did not vividly remember it. Generally, misinformation was more likely to be associated with a know judgment than with a remember judgment after a short retention interval. This outcome suggests that, in many cases, misleading information is judged as having a different subjective quality than memory for actual events. However, over a relatively long retention interval, misinformation that simply added new information about the event was more often judged as remembered.

Adult↗

PubMed2002

[Working memory for movement patterns: a direct comparison of memory spans for body and hand movements in dual-task situations].

In this experiment, 36 participants engaged in one of three span tasks; digit span, body movement span, or hand movement span task, in which they were asked to remember visually presented sequences of digits, whole body movement patterns, or hand movement patterns, respectively. As in a standard memory span procedure, the items within each sequence were recalled in order. Participants were presented with increasingly longer sequences of the items, and span score was defined as the number of items in the longest sequence a participant could recall perfectly. The span tasks were tested under three concurrent task conditions; no concurrent task control, concurrent articulation task, and concurrent body-related movement task. The concurrent movement task interfered with performance on both body movement and hand movement span tasks, but not on the digit span task, while the concurrent articulation task interfered with performance on all of the three span tasks. It is suggested that memory for movement patterns, which is involved in the body and band movement spans, would be mediated by a common motor-processing system.

Hand↗

PubMed2001

Memory of action events: the role of objects in memory of self- and other-performed tasks.

Encoding action phrases by enactment produces better recall than hearing or reading the action phrase. This study examined whether enactment enhances memory relative to observing another perform the same action. Theories of the enactment effect suggest that the complexity of the action, here manipulated by varying the number of objects involved in an action, may determine whether enactment enhances memory relative to observation. The results revealed a consistent subject-performed task advantage across all object conditions; the size of the effect did not vary with increasing task complexity. Additionally, items that included the use of an object were recalled better than those without objects. The results are consistent with the views of Engelkamp and Zimmer (1997) and Backman, Nilsson, & Kormi-Nouri (1993), who argued that the SPT effect is due to motor and/or sensory encoding.

Adult↗

PubMed2003

Partial cross-validation of the Wechsler Memory Scale-Revised (WMS-R) General Memory-Attention/Concentration Malingering Index in a nonlitigating sample.

The Wechsler Memory Scale-Revised (WMS-R) malingering indices proposed by Mittenberg, Azrin, Millsaps, and Heilbronner [Psychol Assess 5 (1993) 34.] were partially cross-validated in a sample of 200 nonlitigants. Nine diagnostic categories were examined, including participants with traumatic brain injury (TBI), brain tumor, stroke/vascular, senile dementia of the Alzheimer's type (SDAT), epilepsy, depression/anxiety, medical problems, and no diagnosis. Results showed that the discriminant function using WMS-R subtests misclassified only 6.5% of the sample as malingering, with significantly higher misclassification rates of SDAT and stroke/vascular groups. The General Memory Index-Attention/Concentration Index (GMI-ACI) difference score misclassified only 8.5% of the sample as malingering when a difference score of greater than 25 points was used as the cutoff criterion. No diagnostic group was significantly more likely to be misclassified. Results support the utility of the GMI-ACI difference score, as well as the WMS-R subtest discriminant function score, in detecting malingering.

Adult↗