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V J Dark

Publications and source records attributed to V J Dark.

10 recordsLinked to original sources
PubMed2000

Conceptual activation of distractors during selection is not sufficient to produce negative priming.

Negative priming (NP) occurs when responses are slower because the targets were distractors on the preceding trial. Word-naming NP occurs only with words that have been presented repeatedly as targets; novel words do not show NP. The activation-inhibition explanation is that representations of repeated-word distractors are activated already and must be inhibited; the inhibition carries over to the next trial. If this explanation is correct, novel-word NP should occur if the word is semantically primed (thus activating its representation) before it occurs as a distractor. In two experiments, there was NP for words from a repeated set, and the magnitude of NP increased when the same word could occur as a target on consecutive trials. There was positive, rather than negative, priming for novel-word targets that had been semantically primed as distractors. Either the activation from semantic priming was not sufficiently strong to require inhibition, or the activation-inhibition hypothesis does not refer to activation of conceptual representations.

Attention↗
PubMed1999

Perceptual implicit memory requires attentional encoding.

Perceptual implicit memory for previously attended and unattended words was measured either in a word-stem completion task or in a perceptual fluency (perceptual identification) task. Subjects (N = 144) first engaged in a focused attention task in which they were to identify one of two words presented for 100, 200, or 300 msec. Words were classified as attended if they were reported during the focused attention task and unattended if they were not. Results for both implicit memory tests indicated reliable perceptual implicit memory for attended words but not for unattended words, regardless of focused attention exposure duration. The results indicate that perceptual implicit memory tasks reflect attentional encoding processes; that is, words must undergo attentional encoding if they are to affect performance on a later perceptual implicit memory test.

Attention↗
PubMed1999

Flanker recall and the flanker validity effect may reflect different attentional processes.

High flanker recall in the correlated flanker task suggests a failure of selective attention. We used a dissociation approach to examine the role of attentional processing of the flankers' identities in the flanker validity effect (FVE). In three experiments, flanker recall decreased as flanker duration decreased, but the FVE was not affected by flanker duration. Masking also produced a dissociation, in that masking decreased flanker recall but the FVE was not affected. Examination of on-line flanker identification suggested that flanker recall was an adequate measure of attentional processing of the flankers' identities on most trials. The results suggest that attentional processing of the flankers' identities is not related to the magnitude of the FVE and is not necessary for it to obtain. Because there is a failure of selective attention, the dissociations suggest that flanker recall and the FVE may reflect different attentional processes.

Attention↗
PubMed1998

Attentional processing of "unattended" flankers: evidence for a failure of selective attention.

Results from research with the flanker task have been used to argue both that flankers are identified without attention and that flanker identification requires attention. In three experiments, we addressed this issue by examining flanker recall. In Experiment 1, we manipulated flanker redundancy, a variable that could influence attention to the flankers, in order to determine whether it affected the magnitude of the flanker effect, the magnitude of flanker recall, or both. Redundancy did not influence the flanker effect, and recall was high in both conditions, suggesting that the flankers were attended. The recall results contradicted those of Miller (1987), the only other study that we could find in which flanker recall was used. In Experiments 2 and 3, we examined differences between Miller's procedure and ours. Although flanker recall was lower when open-ended rather than forced recall was used and when the flanker task was made more complicated, flanker recall remained well above chance in all conditions. The data strongly suggest that in the typical correlated flanker task there is a failure of selective attention at some point during processing such that flankers receive attentional processing.

Adult↗
PubMed1996

Semantic and spatial components of selective attention.

Semantic and spatial effects on selective processing were examined. A prime presented 250 ms or 1,000 ms before a pair of masked words was related to 1 of the words on 1/3 of the trials. Although Experiments 1 and 2 required report of both words, processing was selective; typically, just 1 word could be reported. In Experiment 1, reported words were more often top words, showing spatial selectivity, and more often words related to the prime, showing semantic selectivity. Experiment 2 included to-be-ignored peripheral cues 50 ms before the pair. Related words were reported more often at both delays, and cuing produced an additive benefit at 1,000 ms. Experiment 3 required report of just the cued word and included 100-ms cues. Cued words were reported more often, especially at 1,000 ms and with 100-ms cues, but semantic selectivity also occurred. Selectivity via semantic priming and via location reflect separate attentional mechanisms.

Attention↗
PubMed1992

Do abrupt-onset peripheral cues attract attention automatically?

The proportion of peripheral cues that predicted at which of two locations a discrimination target would occur was manipulated in three experiments. Near cues occurred adjacent to the target and far cues occurred adjacent to the other location. In Experiment 1, near and far cues were presented in separate blocks so each predicted target location. Both types of cue produced benefit relative to a neutral baseline. In Experiment 2 expectancy for near versus far cues was manipulated. In one group, 80% of the peripheral cues were near; in another, only 20% were near; in a third, near and far cues occurred randomly. Near cures always produced benefit. Far cues produced benefit when they were expected, had no effect in the random group, and sometimes produced cost when they were unexpected. Experiment 3 repeated the near-expected and far-expected conditions, but target duration was shortened to 50 msec. A similar pattern emerged, except that near cues produced less benefit at longer SOAs when they were unexpected. The data suggest that peripheral, abrupt-onset cues may produce benefit via an automatic process, but that such a process is more like location priming than the capture of attention. Expectancy determines whether and where attentional resources will be allocated in response to the cue.

Adult↗
PubMed1990

Switching between memory and perception: moving attention or memory retrieval?

Weber, Burt, and Noll (1986) estimated that the time needed to switch attention between memory and perception was around 300 msec. The first two experiments in the present paper estimated switching time using a variation of their task. Subjects reported aloud lists of six items. The items were read off a computer screen (perception), recited from memory, or reported alternately from the two sources. The data show that the switching-time estimate is influenced by input/output compatibility, response-initiation times, and memory load. When these factors were controlled, estimated switching time dropped to around 100-150 msec. The data suggest, however, that the switch from perception to memory might be slower than the switch from memory to perception, which would invalidate the formula used to compute switching time. Experiment 3 tested the time for a single switch from perception to memory and a single switch from memory to perception by restricting report to one pair of items in the list. When the to-be-reported pair was precued, estimated switching time dropped to zero. When the pair was not precued, the memory-to-perception switching time remained at zero, but the perception-to-memory time was more than 400 msec. The pattern of results forced a reconceptualization of the task in terms of memory retrieval rather than attention switching. The attention-switching times appear to reflect processes required to select items from memory.

Adult↗
PubMed1985

Levels of selection and capacity limits.

Subjects performed a visual target-detection task in eight experiments. We examined the effects of word relevancy (word in relevant or irrelevant location) and display load (1-4 words) on physical, semantic, and controlled processing of nontargets. Interwoven with the detection task was a test-word identification task that was used to measure priming potency of nontargets. Physical and semantic levels of processing were measured in terms of identity and semantic priming, respectively. Nontarget primes were repeated as test words in identity priming. Nontarget primes were semantic associates of test words in semantic priming. Controlled processing of nontargets was measured in terms of recognition memory on a subsequent test. All measures increased with word relevancy and decreased with display load. The priming effects remained intact even when word presentation was speeded up and controlled processing was sharply curtailed. The data indicate that all levels of processing are selective and capacity limited.

Adolescent↗
PubMed1982

In defense of intraperceptual theories of attention.

A distinction is drawn between intraperceptual and extraperceptual theories of attention. Only the former class allows for the selective modulation of amount of nonconscious, perceptual processing of concurrent stimuli. The adequacy of intraperceptual theory has been questioned on the basis of diverse empirical findings. This literature is critically examined and is considered inconclusive partly because of the lack of an appropriate measure of amount of perceptual processing. A new experiment that attempts to provide such a measure is reported. Subjects detected names of states of the United States in dichotically presented lists. Subjects either could focus on just one list (relevant list) or had to divide their attention between the two lists. Amount of perceptual processing of a word (e.g., voice or titre) was measured in terms of the extent to which it primed subjects' interpretations of a visually presented homograph (e.g., spoke). Priming potency of words was greatest in the relevant list and was least in the other list. The data support a broad version of intaperceptual theory that allows for birth perceptual facilitation of relevant stimuli and perceptual suppression of irrelevant stimuli.

Attention↗