Biomedical subjects

S Joordens

Publications and source records attributed to S Joordens.

13 recordsLinked to original sources

PubMed2000

Investigating a memory-based account of negative priming: support for selection-feature mismatch.

Using typical and modified negative priming tasks, the selection-feature mismatch account of negative priming was tested. In the modified task, participants performed selections on the basis of a semantic feature (e.g., referent size). This procedure has been shown to enhance negative priming (P. A. MacDonald, S. Joordens, & K. N. Seergobin, 1999). Across 3 experiments, negative priming occurred only when the repeated item mismatched in terms of the feature used as the basis for selections. When the repeated item was congruent on the selection feature across the prime and probe displays, positive priming arose. This pattern of results appeared in both the ignored- and the attended-repetition conditions. Negative priming does not result from previously ignoring an item. These findings strongly support the selection-feature mismatch account of negative priming and refute both the distractor inhibition and the episodic-retrieval explanations.

Adult↗

PubMed2000

Recollection and familiarity through the looking glass: when old does not mirror new.

The authors use the qualitative differences logic to demonstrate that 2 separate memory influences underlie performance in recognition memory tasks, familiarity and recollection. The experiments focus on the mirror effect, the finding that more memorable stimulus classes produce higher hit rates but lower false-alarm rates than less memorable stimulus classes. The authors demonstrate across a number of experiments that manipulations assumed to decrease recollection eliminate or even reverse the hit-rate portion of the mirror effect while leaving the false-alarm portion intact. This occurs whether the critical distinction between conditions is created during the test phase or manipulated during the study phase. Thus, when recollection is present, it dominates familiarity so that the hit-rate portion of the mirror effect primarily reflects recollection; when recollection is largely absent, the opposite pattern associated with the familiarity process emerges.

Adult↗

PubMed2000

Turning an advantage into a disadvantage: ambiguity effects in lexical decision versus reading tasks.

When performing a lexical decision task, participants can correctly categorize letter strings as words faster if they have multiple meanings (i.e., ambiguous words) than if they have one meaning (i.e., unambiguous words). In contrast, when reading connected text, participants tend to fixate longer on ambiguous words than on unambiguous words. Why are ambiguous words at an advantage in one word recognition task, and at a disadvantage in another? These disparate results can be reconciled if it is assumed that ambiguous words are relatively fast to reach a semantic-blend state sufficient for supporting lexical decisions, but then slow to escape the blend when the task requires a specific meaning be retrieved. We report several experiments that support this possibility.

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PubMed1999

Negative priming effects that are bigger than a breadbox: attention to distractors does not eliminate negative priming, it enhances it.

In a series of experiments, we examined the effect of requiring subjects to attend to distractors in a test of negative priming. This was accomplished by using a referent size-selection task in which subjects were instructed to name the larger animal and to ignore the smaller animal in a word pair. The result was a quadrupling of the standard negative priming effect, suggesting that negative priming not only occurs for attended distractors, it is actually enhanced. We demonstrated that this enhancement of the effect was not due solely to increased latencies in the referent size-selection task, because neither decreasing base response times in other referent size-selection tasks nor increasing base response times in typical color-selection tasks substantially affected the respective negative priming effects. Although these findings can be accommodated within current theories of negative priming, they challenge the basic assumption that the negative priming effect arises because the critical item was ignored or not attended to on the prime trial.

Attention↗

PubMed1998

Selective attention: a reevaluation of the implications of negative priming.

The notion that inhibitory processes play a critical role in selective attention has gained wide support. Much of this support derives from studies of negative priming. The authors note that the attribution of negative priming to an inhibitory mechanism of attention draws its support from a common assumption underlying priming procedures, together with the procedure that has been used to measure negative priming. The results from a series of experiments demonstrate that selection between 2 competing prime items is not required to observe negative priming. This result is demonstrated across several experiments in which participants named 1 of 2 items in a second display following presentation of a single-item prime. The implications of these results for existing theories of negative priming are discussed, and a theoretical framework for interpreting negative priming and several related phenomena is forwarded.

Adult↗

PubMed1997

The long and short of semantic priming effects in lexical decision.

Unlike other forms of priming, semantic priming appears only to occur at short lags. In apparent contrast to this, S. Becker, M. Moscovitch, M. Behrmann, and S. Joordens (1997) described a theory of priming that predicts long-term effects for all forms of relatedness. This prediction is reconciled with previous failures to observe long-term semantic priming on the basis of 2 claims: (a) that previously used pairs share few semantic features and (b) that tasks typically used to study priming are not especially sensitive to semantic influences. The present experiments provide further support for these claims by demonstrating long-term semantic priming in the lexical-decision task when the stimuli and task are modified in a way that increases semantic involvement. However, the findings' suggest that in addition to the mechanism advocated by Becker et al., a second mechanism is necessary to provide a complete account of semantic priming effects.

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PubMed1997

Parallels between Perception without Attention and Perception without Awareness

Do studies of perception without awareness and studies of perception without attention address a similar underlying concept of awareness? To answer this question, we compared qualitative differences in performance across variations in stimulus quality (i.e., short vs. long prime-mask stimulus onset asynchrony) with qualitative differences in performance across variations in the direction of attention (i.e., focused vs. divided). The qualitative differences were based on three different phenomena: Stroop priming, false recognition, and exclusion failure. In all cases, variations in stimulus quality and variations in the direction of attention led to parallel findings. These results suggest that perception with and without awareness and perception with and without attention are equivalent ways of describing the same underlying process distinction.

Journal Article↗

PubMed1997

Long-term semantic priming: a computational account and empirical evidence.

Semantic priming is traditionally viewed as an effect that rapidly decays. A new view of long-term word priming in attractor neural networks is proposed. The model predicts long-term semantic priming under certain conditions. That is, the task must engage semantic-level processing to a sufficient degree. The predictions were confirmed in computer simulations and in 3 experiments. Experiment 1 showed that when target words are each preceded by multiple semantically related primes, there is long-lag priming on a semantic-decision task but not on a lexical-decision task. Experiment 2 replicated the long-term semantic priming effect for semantic decisions with only one prime per target. Experiment 3 demonstrated semantic priming with much longer word lists at lags of 0, 4, and 8 items. These are the first experiments to demonstrate a semantic priming effect spanning many intervening items and lasting much longer than a few seconds.

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PubMed1996

Negative priming without overt prime selection.

The procedure typically used to demonstrate negative priming requires subjects to respond to one of two simultaneously presented stimuli across two consecutive displays. Negative priming is defined by slower responses to targets in the second display that appeared as distractors in the first display, than to targets in the second display that did not appear in the first display. It is widely assumed that negative priming occurs as a result of the selection that occurs in the first display. In the present article, we show that negative priming can be observed without requiring subjects to respond selectively to one of two items in the first display. We argue that this result is useful for two reasons. First, it points out a fundamental misunderstanding concerning the procedure required to measure negative priming, a misunderstanding that has shaped much of the theoretical work done in this area. Second, we suggest that the procedure introduced here is of considerable utility in evaluating theoretical accounts of negative priming. To demonstrate this utility we report the results of two studies that assess the code co-ordination account of negative priming.

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PubMed1995

Measuring the relative magnitude of unconscious influences.

As an alternative to establishing awareness thresholds, stimulus contexts in which there were either greater conscious or greater unconscious influences were defined on the basis of performance on an exclusion task. Target words were presented for brief durations and each target word was followed immediately by its three-letter stem. Subjects were instructed to complete each stem with any word other than the target word. With this task, failures to exclude target words indicate greater unconscious influences, whereas successful exclusion indicates greater conscious influences. Conscious influences were dominant at long durations (e.g., 214 ms), but unconscious influences were dominant at short durations (e.g., 50 ms). Performance on the exclusion task successfully predicted both qualitative differences in Stroop priming and qualitative differences in recognition memory previously associated with the different effects of conscious and unconscious influences. Taken together, these results demonstrate that an exclusion task allows both unconscious and conscious influences to be defined in terms of significant deviations from baseline performance. As such, exclusion tasks provide a method for distinguishing conscious from unconscious influences that does not require establishing thresholds for null awareness.

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PubMed1992

Priming effects that span an intervening unrelated word: implications for models of memory representation and retrieval.

Several studies have reported priming effects that span an intervening unrelated word (Davelaar & Coltheart, 1975; Meyer, Schvaneveldt, & Ruddy, 1972). More recently, other investigators have suggested that such relatedness effects are the result of postaccess processes (Gough, Alford, & Holley-Wilcox, 1981; Masson, 1991; Ratcliff & McKoon, 1988). In fact, these investigators claim that when procedures are used that discourage the use of postaccess processes, relatedness effects do not span intervening unrelated words. The present experiments demonstrate reliable relatedness effects with procedures that eliminate postaccess processes. These results are consistent with the notion of spreading activation among local representations in memory. Implications for the issue of local versus distributed representations are discussed.

Adult↗

PubMed1992

False recognition and perception without awareness.

Jacoby and Whitehouse (1989) demonstrated that the probability of calling new test words "old" (i.e., false recognition) is biased by context words. When context words were briefly exposed and subjects were not informed of their presence, new words were called "old" more often if the context and test words were identical than if the context and test words were different. When the context words were presented at longer exposure durations and subjects were informed of their presence, the opposite pattern of results occurred. In Experiment 1, we replicated the critical qualitative difference across conditions reported by Jacoby and Whitehouse. In addition, the combined results of Experiments 2 and 3 demonstrated that the exposure duration of the context words, and not the instructions to the subjects, is the primary factor determining which pattern of false recognition occurs. However, in contrast with the findings of Jacoby and Whitehouse, both patterns of false recognition were associated with significant recognition memory for the context words. The latter finding presents problems for any interpretation of false recognition, which implies that the briefly exposed context words are perceived without awareness.

Adult↗

PubMedDate not supplied

Parallels between perception without attention and perception without awareness.

Attention↗