Parallel memory retrieval in dual-task situations: I. Semantic memory.

Can participants retrieve information about the 2nd of 2 stimuli while they are processing the 1st? Four experiments suggest they can. Reaction times to the 1st stimulus were faster if it came from the same category as the 2nd than if it came from a different category. This category-match effect was observed for letter-digit discrimination (Experiment 1), magnitude and parity judgments about digits (Experiment 2), and lexical decisions (Experiment 3). Experiment 4 showed that the 2nd stimulus could semantically prime the 1st. The category-match effect was observed only when the same task was performed on the 2 stimuli. When the task changed from the Ist stimulus to the 2nd, there was no advantage of a category match. This dependence on task set may explain previous failures to find parallel retrieval. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Semantic memory in Alzheimer's disease.

Patients with Alzheimer's disease have been suggested to have a semantic memory impairment not present in the normal old. This article reviews the performance of Alzheimer patients on tests of various aspects of semantic memory, including word finding, knowledge of the semantic attributes, and associates of concepts, as well as their category membership. The effect that semantic context has on cognitive processes such as lexical and semantic priming and memory encoding is also reviewed. Finally, the ability of theoretical constructs such as implicit memory and automaticity to explain intertask variability in Alzheimer patients' semantic performance is discussed. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Semantic activation and episodic memory: Age similarities and differences.

In 2 experiments, 48 19–35 yr olds and 48 59–75 yr olds were engaged in semantic and nonsemantic orienting tasks and were subsequently given incidental or expected recall and recognition tasks. Reaction time (RT) patterns from the orienting tasks suggested that all Ss experienced similar semantic activation during encoding. Under incidental conditions, age differences in memory performance were minimal. When memory tests were expected, younger Ss recalled and recognized more items than did older Ss, suggesting that younger Ss were more effective in their deployment of mnemonic strategies. The age difference was particularly pronounced for unattended items, which suggests an age difference in the capacity to encode all of the episodic information. (31 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Cognitive integration of language and memory in bilinguals: Semantic representation.

Understanding cognitive research on the integration of 2 languages in bilingual memory is difficult because of the different terminology, methodology, analysis, and interpretation strategies that scholars with different backgrounds bring to the research. These studies can be usefully categorized on 2 dimensions: memory for verbal experience versus linguistic knowledge, and systemwise versus pairwise issues. Experimental findings in this area converge on the conclusion that at the word meaning/conceptual level, both episodic and linguistic memory can be characterized as shared at the systems level and at least partly shared at the pairwise translation-equivalent level. Interpretation problems that stem from weak hypothesis testing structure and from covert translation can be minimized by using appropriate design and analysis techniques. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Semantic memory content in permastore: Fifty years of memory for Spanish learned in school.

Tested retention of Spanish among 587 Ss who had studied the language in high school or college 1–50 yrs previously. Also tested were 146 Ss currently studying Spanish and 40 who had never studied Spanish. Tests of reading comprehension, recall, recognition vocabulary, and grammar were administered together with a questionnaire to determine the level of original training, the grades received, and rehearsals during the retention interval in the form of reading, writing, speaking, or listening to Spanish. Analysis showed that retention throughout the 50-yr period was predictable on the basis of the level of original training. Data reveal no significant rehearsal effects. The analysis yielded memory curves that declined exponentially for the 1st 3–6 yrs of the retention interval. After that, retention remained unchanged for up to 30 yrs before showing a final decline. Large portions of the originally acquired information remained accessible; the portion of the information in a "permastore" state was a function of the level of original training, the grades received in Spanish courses, and the method of testing (recall vs recognition). (26 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Semantic memory in Alzheimer's disease: Representativeness, ontologic category, and material.

Alzheimer's disease (AD) patients with semantic memory difficulty and AD patients with relatively preserved semantic memory named pictures and judged the category membership of words and pictures of natural kinds and manufactured artifacts that varied in their representativeness. Only semantically impaired patients were insensitive to representativeness in their category judgments. AD subgroup judgments did not differ for natural kinds compared to manufactured artifacts nor for words compared to pictures. AD subgroup differences could not be explained by dementia severity, memory, reading, and visuoperception. The similarity process for relating coordinate members of a taxonomic category contributes to the normal appreciation of word and picture meaning, and this process is compromised in AD patients with semantic difficulty. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Semantic knowledge and episodic memory for faces in semantic dementia.

Previous studies have documented poor recognition memory for faces in patients with semantic dementia. Preserved face recognition memory was found in this study, however, so long as atrophy was confined predominantly to the left temporal lobe. Patients with structural damage to the right temporal lobe were typically impaired, with the status of the hippocampus and parahippocampal gyrus (including the perirhinal cortex) on the right being critical. Two single-case studies of patients with predominantly left temporal lobe pathology confirmed good recognition memory for famous faces, even if semantic knowledge about the celebrities depicted was severely degraded. An effect of semantic knowledge on recognition memory became apparent only when perceptually different photographs of the famous people were used at study and test. These results support the view that new episodic learning typically draws on information from both perceptual and semantic systems. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Semantic memory is impaired in schizophrenia

Memory is emerging as a key area of neuropsychological deficit in schizophrenia, with evidence suggesting that the impairment is restricted to long-term memory. Semantic memory, the component of long-term memory containing stored representations of the meanings of words and knowledge about the world, was examined in 46 schizophrenic patients and 40 normal controls using a recently devised battery of tests. Evidence of semantic memory impairment was found which was wide ranging and substantial; in some cases it approached the levels seen in a group of 22 patients with mild-to-moderate Alzheimer's disease. Both group analysis and a more detailed examination of two single cases suggested that semantic memory impairment represents a disproportionate and possibly specific neuropsychological deficit in schizophrenia.     

On telling the whole story: Facts and interpretations in autobiographical memory narratives from childhood through midadolescence.

This article examines age differences from childhood through middle adolescence in the extent to which children include factual and interpretive information in constructing autobiographical memory narratives. Factual information is defined as observable or perceptible information available to all individuals who experience a given event, while interpretive information is defined as information that articulates the desires, emotions, beliefs, and thoughts of the participant and other individuals who experience an event. Developmental research suggests that the latter type of information should become particularly prevalent in later adolescence, while the former should be abundantly evident by age 8. Across 2 studies, we found evidence for strong increases in interpretive information during adolescence, but not before. These increases were evident across different types of events, and across different subtypes of interpretive content. The results are discussed in terms of their implications for the development of autobiographical memory in childhood and adolescence. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Semantic processing and memory for attended and unattended words in dichotic listening: Behavioral and electrophysiological evidence.

Thirty-two Ss studied words presented to 1 ear, while ignoring a concurrent word list presented to the opposite ear. The N400 component of the event-related potentials elicited by attended words was modulated by semantic priming between successive words. The N400 elicited by unattended words was insensitive to semantic manipulation. Recognition memory was better for attended than for unattended words. However, the percentage of false positives was elevated equally for lures that were semantically related to "old" words, whether they had been attended or unattended. Words that were initially attended induced similar repetition effects in a lexical decision task as words that were initially unattended. Hence, both attended and unattended words are semantically processed and activate semantic representations. However, attended words form traces that are subsequently more available to conscious recollection than unattended words. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Semantic memory in Alzheimer's disease and the frontotemporal dementias: A longitudinal study of 236 patients.

Using semantic dementia (SD) as a reference point, the authors assessed semantic memory in four other neurodegenerative disorders: progressive nonfluent aphasia (PNFA), frontal variant frontotemporal dementia (fvFTD), Alzheimer's disease (AD), and posterior cortical atrophy (PCA). Individuals with SD were more impaired than other groups on semantic measures and showed a characteristic pattern across tasks: category fluency (CF) worse than letter fluency (LF), naming worse than comprehension, and visual and verbal comprehension equally affected, suggesting disruption to an amodal semantic system. Individuals with AD demonstrated a similar pattern to a milder degree. Although PNFA, fvFTD, and PCA groups had abnormal scores (relative to controls) on most semantic measures, their differing patterns across measures indicate that the apparent semantic impairment in these conditions is largely secondary to other factors. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Integrity tests: Facts and unresolved issues.

Describes 2 independent reports, recently completed by the American Psychological Association (APA) and the US Congress Office of Technology Assessment, that examined many scientific and measurement issues concerning integrity testing (e.g., validity, criterion relevance). Background data are offered on a variety of tests collected by a survey of test publishers, providing a view of the industry's scope (e.g., test audience, user screening, score reporting) not available elsewhere. In the light of APA's Ethical Principles for Psychologists and Code of Conduct (APA, 1992), unresolved concerns are addressed that have a wide range of implications for the profession of psychology, the testing industry, and public policy (e.g., cutting scores, user screening and training, and test marketing practices). (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Testing global memory models using ROC curves.

Global memory models are evaluated by using data from recognition memory experiments. For recognition, each of the models gives a value of familiarity as the output from matching a test item against memory. The experiments provide ROC (receiver operating characteristic) curves that give information about the standard deviations of familiarity values for old and new test items in the models. The experimental results are consistent with normal distributions of familiarity (a prediction of the models). However, the results also show that the new-item familiarity standard deviation is about 0.8 that of the old-item familiarity standard deviation and independent of the strength of the old items (under the assumption of normality). The models are inconsistent with these results because they predict either nearly equal old and new standard deviations or increasing values of old standard deviation with strength. Thus, the data provide the basis for revision of current models or development of new models. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Semantic priming in fully recurrent network models of lexical knowledge.

The claim that A E. Masson's (1995) model of lexical knowledge provides an account of semantic priming is evaluated in a series of simulations. It was found that although a semantically unrelated prime produces slower simulated naming of the target word than a related prime, the difference reflects interference by the unrelated prime and not facilitation by the related prime, which has little absolute effect. The facilitation reported by Masson was produced by the simulated "neutral" stimulus that intervened between prime and target, not by the semantically related prime. Simulations of a stochastic variant of Masson's model and a "brain-state-in-a-box" model of word naming also failed to produce semantic facilitation, raising the possibility that in fully connected recurrent networks, facilitation does not occur via indirect collateral pathways. Methodological implications for evaluating priming in simulated networks are raised. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Connectionist models of recognition memory: Constraints imposed by learning and forgetting functions.

Multilayer connectionist models of memory based on the encoder model using the backpropagation learning rule are evaluated. The models are applied to standard recognition memory procedures in which items are studied sequentially and then tested for retention. Sequential learning in these models leads to 2 major problems. First, well-learned information is forgotten rapidly as new information is learned. Second, discrimination between studied items and new items either decreases or is nonmonotonic as a function of learning. To address these problems, manipulations of the network within the multilayer model and several variants of the multilayer model were examined, including a model with prelearned memory and a context model, but none solved the problems. The problems discussed provide limitations on connectionist models applied to human memory and in tasks where information to be learned is not all available during learning. (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)     

Coffee. Facts and controversies

Despite difficulties in differential diagnosis, aspiration cytology offers unique advantages in the preoperative diagnosis of Hürthle cell (HC) tumors of the thyroid gland over immunocytochemistry and micromorphometry, which have not achieved the anticipated success in the diagnosis of HC tumors. Aspiration cytology is comparable, in terms of speed and accuracy, to microspectrometry of DNA content in HC tumors, a technique that is not convenient for routine use. Detailed morphologic analysis of 19 characteristics of the smears and of the cells revealed five parameters adding to the sensitivity, specificity and reliability of routine diagnosis: HC collection in the form of nests, marked or at least moderate anisocytosis and anisokaryosis, multinucleation and emphasized nucleoli. All five criteria are found in > 70% of HC tumors, and the rate of false positives is < 50%. The simultaneous presence of three or four of these five parameters occurred in 70-90% of HC tumors and would lead to a false-positive diagnosis of HC tumors in only 30% of cases. Routine cytologic diagnosis of HC tumors of the thyroid gland may be improved by adoption of these criteria.     

Retention curves: Facts or artifacts.

Retention curves based upon recognition scores may be comparable in slope and amount of retention to curves based upon recall and anticipation performance. Previous contrary conclusions are overgeneralized. They are the result of the selection of easy recognition tests and failure to control the variable of overlearning. Measures of recognition, free recall and anticipation are dichotomous, and the slopes of curves based upon such measures are artifacts of the changing sensitivity of the measure. The curves can therefore not provide the basis for general conclusions regarding relative amounts of forgetting over different time periods. (20 ref.) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Psychiatric hospital admission rates: Facts and artifacts.

Examined types of patient admissions in the 1st yr of a new psychiatric hospital opening to address issues raised by I. Silverman and D. Saunders (see record 1982-01855-001). It was found that, for all patients residing in the county where the new facility was located, 39%, 48%, and 13% were transfer admissions, readmissions, and 1st admissions, respectively. By using a more valid definition of the same criterion variable (admission rates), these results question Silverman and Saunders's interpretation of the same data. (French abstract) (3 ref) (PsycINFO Database Record (c) 2011 APA, all rights reserved)