Biomedical subjects

N W Mulligan

Publications and source records attributed to N W Mulligan.

12 recordsLinked to original sources

PubMed2001

Generation and hypermnesia.

The multifactor account of the generation effect makes detailed predictions about the effects of generation on item-specific and relational encoding, predictions confirmed in four experiments using a multiple-test methodology. In pure-list designs with unrelated study items, generation produced more interest item gains (indexing greater item-specific processing) and more interest item losses (indexing less relational processing) relative to the read condition. In a mixed-list design, generation produced more gains but did not affect losses. With categorically-related study items, generation produced more gains but fewer losses (indicating enhanced relational encoding). Generation consistently produced hypermnesia whereas reading did so only for related study items. Also, a significant generation effect emerged on later tests under conditions (between-subjects design, unrelated study items) which typically yield no generation effect.

Adult↗

PubMed2001

Word frequency and memory: effects on absolute versus relative order memory and on item memory versus order memory.

Word frequency can produce opposite effects on recognition and order memory: Low-frequency words produce greater recognition accuracy, whereas high-frequency words produce superior order memory. The present experiments further delineate the relationship between word frequency and order memory. Experiment 1 indicates that low-frequency words produce worse performance on a measure of absolute order memory but not on a test of relative order, which is consistent with the idea that different forms of information underlie different types of order judgments (Greene, Thapar, & Westerman, 1998). Experiment 2 contrasted high-, low-, and very low-frequency words on recognition memory and absolute order memory. In comparison with high-frequency words, low-frequency words enhanced recognition, whereas very low-frequency words did not. Both low- and very low-frequency words, however, produced worse memory for absolute order. Thus, the relationship between frequency and item memory is an inverted U-shaped function, whereas the relationship between frequency and absolute order memory is direct. This implies that the item-enhancing effects of lower word frequency may be dissociated from its order-disrupting effects.

Adult↗

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↗

PubMed2000

Attention and perceptual priming in the perceptual identification task.

Prior research indicates that manipulations of attention during encoding sometimes affect perceptual implicit memory. Two hypotheses were investigated. One proposes that manipulations of attention affect perceptual priming only to the extent that they disrupt stimulus identification. The other attributes reduced priming to the disruptive effects of distractor selection. The role of attention was investigated with a variant of the Stroop task in which participants either read words, identified their color, or did both. Identifying the color reduced priming even when the word was also overtly identified. This result held regardless of whether color and word were presented as a single object (Experiments 1 and 2) or as separate objects (Experiment 4). When participants read and identified a color, the overt order of the responses did not matter; both conditions reduced priming relative to reading alone (Experiment 3). The results provide evidence against the stimulus-identification account but are consistent with the distractor-selection hypothesis.

Adult↗

PubMed2000

Perceptual interference at encoding enhances item-specific encoding and disrupts relational encoding: evidence from multiple recall tests.

Interfering with perception during encoding can enhance later memory, a phenomenon known as the perceptual interference effect. This effect is investigated in the context of the item-specific-relational framework (e.g., Hunt & McDaniel, 1993), which suggests that the perceptual interference enhances item-specific encoding and impedes relational encoding. Two experiments performed with multiple recall tests support this view. Prior research indicates that item-specific processing increases item gains across tests, whereas relational processing protects against item losses (e.g., Burns, 1993; Klein, Loftus, Kihlstrom, & Aseron, 1989). Consistent with the item-specific-relational framework, perceptual interference produced significant increases in both item gains and losses relative to a control condition.

Adult↗

PubMed1999

The effects of perceptual interference at encoding on organization and order: investigating the roles of item-specific and relational information.

Interfering with the perceptual processing of a stimulus can improve memory. The perceptual-interference effect was investigated from the perspective of the item-specific/relational encoding distinction. This perspective suggests that perceptual interference enhances item-specific encoding but disrupts the encoding of relational and order information. The results of 6 experiments were largely consistent with this view. In Experiments 1 and 2, perceptual interference (a hypothesized item-specific manipulation) and list organization (a relational manipulation) both enhanced free recall but had opposite effects on a measure of relational processing (category clustering). Increasing list organization increased clustering, whereas perceptual interference decreased clustering. In addition, perceptual interference typically decreased memory for order. Finally, when order information was an important determinant of free recall, the perceptual-interference effect was eliminated or reversed. When reliance on order information was lessened, the perceptual-interference effect reemerged.

Adult↗

PubMed1999

The effects of levels-of-processing and organization on conceptual implicit memory in the category exemplar production test.

The distinction between item-specific and relational information (Hunt & Einstein, 1981) may be relevant to accounts of conceptual priming in the category exemplar production task. In three experiments, the implications of this hypothesis were tested by examining the effects of organization and levels-of-processing (LOP) on this implicit test. Consistent with the hypothesis, the effects of LOP were greater when study lists were organized by category than when they were presented randomly. Furthermore, when subjects claiming test awareness or intentional retrieval were excluded from the analysis, the LOP effect was reduced (and, in fact, eliminated) in the random list condition but remained robust in the categorized condition. Finally, the experimental design of the LOP manipulation (i.e., mixed-list within, blocked-list within, or between subjects) did not moderate the effects of LOP on this priming task.

Adult↗

PubMed1998

The role of attention during encoding in implicit and explicit memory.

In 5 experiments, participants read study words under conditions of divided or full attention. Dividing attention reduced performance on the general knowledge test, a conceptual implicit test of memory. Likewise, dividing attention reduced conceptual priming on the word--association task, as well as on a matched explicit test, associate-cued recall. In contrast, even very strong division of attention did not reduce perceptual priming on word-fragment completion, although it did reduce recall on the matched explicit test of word-fragment-cued recall. Finally, dividing attention reduced recall on the perceptual explicit tests of graphemic-cued recall and graphemic recognition. The results indicate that perceptual implicit tests rely minimally on attention-demanding encoding processes relative to other types of memory tests. The obtained pattern of dissociations is not readily accommodated by the transfer-appropriate-processing (TAP) account of implicit and explicit memory. Potential extensions of the TAP view are discussed.

Attention↗

PubMed1997

Improving cardiopulmonary resuscitation skills retention: effect of two checklists designed to prompt correct performance.

Previous research has shown that regardless of an individual's experience, life support skills such as cardiopulmonary resuscitation (CPR) are poorly performed as soon as 1 month following training. The purpose of this study was to compare the effects of two checklists designed to prompt correct CPR performance. We compared the performance of 169 undergraduate students, at the time of course assessment, with retention testing that occurred 2 months following the course assessment. Students were randomly assigned to a control group, a short version of a CPR checklist and a longer more detailed version. Two groups of variables were created: procedural and compression-ventilation variables. In addition, an overall-performance variable was created, summarizing performance on the procedural variables. Binary variables were assessed with chi 2-tests of independence. One-way ANOVAs, using 'group' as the between-subjects factor, were used to assess each continuous variable. Comparisons between groups yielded significant differences of P < 0.05. The long checklist generally led to superior performance on the procedural variables. The results support the hypothesis that remembering the steps of CPR is too complex for some. Though preliminary, the findings of this study indicate that the detailed checklist was an effective strategy to improve the post-course performance of CPR.

Cardiopulmonary Resuscitation↗

PubMed1997

Attention and implicit memory tests: the effects of varying attentional load on conceptual priming.

The role of attention during encoding is important to many current accounts of the implicit/explicit memory distinction. Some accounts suggest that implicit memory tests reflect automatic (non-attention-demanding) encoding processes, whereas other accounts (such as the transfer-appropriate-processing view) suggest that performance on conceptual implicit tests requires attention during encoding. The present study manipulates attention at encoding over several levels (by varying short-term memory load) and examines the effects on the category-exemplar production task (a conceptual implicit memory test) and its explicit counterpart, category-cued recall. Dividing attention decreased performance on both tests, but in different ways. Mild divisions of attention reduced recall but not conceptual priming. Strong divisions of attention reduced performance on both tests and, in addition, eliminated conceptual priming entirely. These findings resolve apparently conflicting results in the literature and help to clarify the relationship between attention and performance on implicit memory tests.

Adult↗

PubMed1996

The effects of perceptual interference at encoding on implicit memory, explicit memory, and memory for source.

Interfering with stimulus identification can enhance later explicit memory performance. This counterintuitive (and theoretically unexpected) phenomenon was investigated in 5 experiments. Perceptual interference enhanced category-cued recall (a conceptually driven explicit test) but had no effect on a comparable implicit memory test, category-exemplar production. This dissociation was obtained across higher levels of priming and with high-frequency as well as low-frequency exemplars. Furthermore, although perceptual interference enhanced old-new recognition memory, it did not enhance rhyme recognition (a data-driven explicit test) or source discriminability. Explanations based on enhanced semantic elaboration or enhanced encoding of spatio-temporal context do not account for the perceptual-interference effect. An account based on compensatory processing of higher level perceptual representations remains viable and is discussed in terms of the transfer-appropriate processing framework and the item-specific-relational distinction.

Adult↗

PubMed1996

Divided attention and indirect memory tests.

Attentional state during acquisition is an important determinant of performance on direct memory tests. In two experiments we investigated the effects of dividing attention during acquisition on conceptually driven and data-driven indirect memory tests. Subjects read a list of words with or without distraction. Memory for the words was later tested with an indirect memory test or a direct memory test that differed only in task instructions. In Experiment 1, the indirect test was category-exemplar production (a conceptually driven task) and the direct test was category-cued recall. In Experiment 2, the indirect test was word-fragment completion (a data-driven task) and the direct test was word-fragment cued recall. Dividing attention at encoding decreased performance on both direct memory tests. Of the indirect tests, category-exemplar production but not word-fragment completion was affected. The results indicate that conceptually driven indirect memory tests, like direct memory tests, are affected by divided attention, whereas data-driven indirect tests are not. These results are interpreted within the transfer-appropriate processing framework.

Adult↗