A familiar pattern? Semantic memory contributes to the enhancement of visuo-spatial memories

In this study we quantify for the first time electrophysiological components associated with incorporating long-term semantic knowledge with visuo-spatial information using two variants of a traditional matrix patterns task. Results indicated that the matrix task with greater semantic content was associated with enhanced accuracy and RTs in a change-detection paradigm; this was also associated with increased P300 and N400 components as well as a sustained negative slow wave (NSW). In contrast, processing of the low semantic stimuli was associated with an increased N200 and a reduction in the P300. These findings suggest that semantic content can aid in reducing early visual processing of information and subsequent memory load by unitizing complex patterns into familiar forms. The N400/NSW may be associated with the requirements for maintaining visuo-spatial information about semantic forms such as orientation and relative location. Evidence for individual differences in semantic elaboration strategies used by participants is also discussed.     

The effects of gender on the retrieval of episodic and semantic components of autobiographical memory

Despite consistent evidence that women exhibit greater episodic memory specificity than men, little attention has been paid to gender differences in the production of episodic details during autobiographical recall under conditions of high and low retrieval support. Similarly the role of gender on the production of semantic details used to support autobiographical memory recollections of specific events has been largely unexplored. In the present study an undergraduate sample of 50 men and 50 women were assessed using the Autobiographical Interview (Levine, Svoboda, Hay, Winocur, & Moscovitch, 2002). Women recalled more episodic information compared to men in the high retrieval support condition, whereas no gender differences were found in the low retrieval support condition. In addition, women produced more repetitions compared to men in the high retrieval support condition. No gender differences were found in the production of semantic details. These results are interpreted in terms of gender differences in encoding and reminiscence practices. This research adds to the literature on gender differences in memory recall and suggests that gender is an important variable in explaining individual differences in AM recall.     

Type-specific proactive interference in patients with semantic and phonological STM deficits

Prior neuropsychological evidence suggests that semantic and phonological components of short-term memory (STM) are functionally and neurologically distinct. The current paper examines proactive interference (PI) from semantic and phonological information in two STM-impaired patients, DS (semantic STM deficit) and AK (phonological STM deficit). In Experiment 1 probe recognition tasks with open and closed sets of stimuli were used. Phonological PI was assessed using nonword items, and semantic and phonological PI was assessed using words. In Experiment 2 phonological and semantic PI was elicited by an item recognition probe test with stimuli that bore phonological and semantic relations to the probes. The data suggested heightened phonological PI for the semantic STM patient, and exaggerated effects of semantic PI in the phonological STM case. The findings are consistent with an account of extremely rapid decay of activated type-specific representations in cases of severely impaired phonological and semantic STM.     

Age-Related Differences in Memory Illusions: Revelation Effect

Older adults are often more susceptible to various illusions and distortions of memory than young adults. In the experiments reported here, we explored the question of whether normal aging was associated with a larger revelation effect, an illusion of memory in which items that are revealed gradually during a recognition test are more likely to be called old than unrevealed items that are shown in their entirety. Contrary to expectations, older adults were not susceptible to this memory illusion. A revelation effect occurred for young but not older adults, even when older adults were similar to young adults on measures of recognition and repetition priming. When data across experiments were combined, there was evidence for a negative revelation effect in older adults in which revealed items were less likely called old than unrevealed items. These results place boundary conditions on the claim that older adults are more susceptible than young adults to memory illusions, and imply that one or more mechanisms underlying the revelation effect are age sensitive.     

Adult Age Differences in Attention to Semantic Context

ABSTRACT

In three experiments age differences in attention to semantic context were examined. The performance of younger adults (ages 18–29 years) and older adults (ages 60–79 years) on a semantic priming task indicated that both age groups could use information regarding the probability that a prime and target would be related to flexibly anticipate the target category given the prime word (Experiment 1). The timing by which target expectancies were reflected in reaction time performance was delayed for older adults as compared to younger adults, but only when the target was expected to be semantically unrelated to the prime word (Experiment 2). When the target and prime were expected to be semantically related, the time course of priming effects was similar for younger and older adults (Experiment 3). Together the findings indicate that older adults are able to use semantic context and the probability of stimulus relatedness to anticipate target information. Although aging may be associated with a delay in the timing by which controlled expectancies are expressed, these findings argue against an age-related decline in the ability to represent contextual information.     

Semantic Hyperpriming in Normal Aging: A Consequence of Instructions?

Abstract

Semantic hyperpriming has consistently been found in normal aging. However, because the standard instructions to test semantic priming are generally ambiguous (focusing on both accuracy and speed), it is difficult to account for hyperpriming in older adults. By using the direct and mediated priming paradigms, this study investigates whether older adults' response mode at testing may explain hyperpriming. First, we show that, under identical conditions, inducing a response mode that favors speed leads to greater priming effects in older adults. The pattern of results is similar to what is observed under standard instructions. Second, prompting a response mode that favors accuracy leads to greater priming effects in younger adults. We discuss various explanations for these findings and conclude, in accordance with the Ratcliff, Thapar, Gomez, and McKoon (2004a Ratcliff, R., Thapar, A., Gomez, P. and McKoon, G. 2004a. A diffusion model analysis of the effects of aging in the lexical-decision task. Psychology and Aging, 19: 278–289. [Crossref], [PubMed], [Web of Science ®] , [Google Scholar]) diffusion model, that hyperpriming in normal aging is contingent on older adults' response mode at testing.     

Unconscious task set priming with phonological and semantic tasks

Whether unconscious stimuli can modulate the preparation of a cognitive task is still controversial. Using a backward masking paradigm, we investigated whether the modulation could be observed even if the prime was made unconscious in 100% of the trials. In two behavioral experiments, subjects were instructed to initiate a phonological or semantic task on an upcoming word, following an explicit instruction and an unconscious prime. When the SOA between prime and instruction was sufficiently long (84 ms), primes congruent with the task set instruction led to speedier responses than incongruent primes. In the other condition (36 ms), no task set priming was observed. Repetition priming had the opposite tendency, suggesting the observed task set facilitation cannot be ascribed solely to perceptual repetition priming. Our results therefore confirm that unconscious information can modulate cognitive control for currently active task sets, providing sufficient time is available before the conscious decision.     

Semantic priming in French children with varying comprehension skills

Semantic priming was analysed in two groups of French children contrasted on comprehension skills with a visual lexical-decision task using a long SOA (800 ms). Two relation types between related primes and targets were examined: pure semantic relation (categorical vs. functional), and lexical association strength (strong vs. weak). Targets were preceded by related, unrelated, and neutral primes. Skilled comprehenders showed semantic priming only for category-related words, whatever their association strength, and without any evidence of an associative boost. Less-skilled comprehenders also showed semantic priming for category-related words, irrespective of their association strength, but with an indication of an associative boost. They also displayed semantic priming for function-related awords that are strongly associated, but not for those that are weakly associated. These results are discussed within the theoretical frame proposed by Plaut and Booth (2000 Plaut, D. C. and Booth, J. R. 2000. Individual and developmental differences in semantic priming: Empirical and computational support for a single-mechanism account of lexical processing. Psychological Review, 4: 786–823.  [Google Scholar]).     

Judging a book by its cover and its contents: the representation of polysemous and homophonous meanings in four-year-old children

Unlike homophonous meanings, which are semantically unrelated (e.g., the use of bat to refer to a baseball bat and a flying rodent), polysemous meanings are systematically related to one another (e.g., the use of book, CD, and video to refer to physical objects, as in ‘the leather book’, or to the intellectual content they contain, as in ‘the profound book’). But do perceived relations among polysemous meanings reflect the presence of generative lexical or conceptual structures that permit the meanings of these words to shift? If so, these structures may also support children’s early representations of polysemous meanings. In four studies, we demonstrate (1) that four-year-old children can understand both the concrete and abstract meanings of words like book, (2) that when taught a novel label for one of these meanings, children can readily understand an extension of that label to the other meaning, and (3) that extension does not occur between two homophonous meanings, which share a common phonological form but are otherwise unrelated. We conclude that the polysemous meanings of words like book rely on a common representational base early in development, and suggest that this may be the result of foundational, generative properties of the lexicon or conceptual system.