Biomedical subjects

Neil W Mulligan

Publications and source records attributed to Neil W Mulligan.

17 recordsLinked to original sources

PubMed2006

Generation and context memory.

Generation enhances memory for occurrence but may not enhance other aspects of memory. The present study further delineates the negative generation effect in context memory reported in N. W. Mulligan (2004). First, the negative generation effect occurred for perceptual attributes of the target item (its color and font) but not for extratarget aspects of context (location and background color). Second, nonvisual generation tasks with either semantic or nonsemantic generation rules (antonym and rhyme generation, respectively) produced the same pattern of results. In contrast, a visual (or data-driven) generation task (letter transposition) did not disrupt context memory for color. Third, generating nonwords produced no effect on item memory but persisted in producing a negative effect on context memory for target attributes, implying that (a) the negative generation effect in context memory is not mediated by semantic encoding, and (b) the negative effect on context memory can be dissociated from the positive effect on item memory. The results are interpreted in terms of the processing account of generation. The original, perceptual-conceptual version of this account is too narrow, but a modified processing account, based on a more generic visual versus nonvisual processing distinction, accommodates the results.

Color Perception↗

PubMed2006

Hypermnesia and total retrieval time.

Recall performance sometimes improves over repeated recall attempts, a phenomenon dubbed hypermnesia. A critical theoretical issue is whether hypermnesia is due to repeated testing per se or increased retrieval time. The present experiments investigated by contrasting five testing conditions. All participants were presented with the same study list followed by either two shorter recall tests or a single longer test. In the multiple test conditions, the tests were either separated by a (filled) 7-minute interval (the multiple-split condition), or presented consecutively, with no break (the multiple-immediate condition). In the single test conditions, the test either began at the start of the recall session, after a (filled) 7-minute delay, or with a 7-minute interruption inserted in the middle. The multiple-split condition produced more reminiscence and hypermnesia than the multiple-immediate condition. More importantly, the multiple-split condition produced greater cumulative recall than any of the other conditions (which did not differ among themselves). That is, single and repeated recall tests of equal total duration are not functionally equivalent.

Amnesia↗

PubMed2006

An asymmetry between memory encoding and retrieval. Revelation, generation, and transfer-appropriate processing.

Transfer-appropriate-processing accounts of memory emphasize the similarity of encoding and retrieval processes, and imply that experimental manipulations should have similar effects on encoding and retrieval. Exceptions to this expectation are thus of great interest, but extant exceptions (produced by studies using divided attention, alcohol, and benzodiazepines) are debatable, single dissociations between encoding and retrieval. The present experiments demonstrate a reversed dissociation, in which the same variable produced opposite effects when implemented at encoding and retrieval. At encoding, participants either solved anagrams of study words or read intact study words. At retrieval, participants likewise solved anagrams or read intact words prior to making recognition memory judgments. Compared with reading intact words, solving anagrams at encoding enhanced later recognition accuracy, whereas solving anagrams at test impaired accuracy. These results were obtained with old/new decisions (Experiment 1) and with confidence ratings (Experiment 2).

Adult↗

PubMed2006

Exploring the role of attention during memory retrieval: effects of semantic encoding and divided attention.

Research on attention and memory suggests that semantic encoding leads to retrieval that is highly susceptible to divided attention. Three experiments tested this proposition and showed that dividing attention did not selectively affect semantically encoded items. Participants encoded a list of words in one of two ways: semantically or phonetically. Later, memory was assessed using either a standard recognition test (Experiment 1) or a rhyme recognition test (Experiments 2 and 3). The participants took the memory test either alone (full attention) or while simultaneously performing a secondary task (divided attention). Recognition accuracy was reduced by divided attention on both recognition tests, and semantically and phonetically encoded words were equally affected.

Attention↗

PubMed2004

Total retrieval time and hypermnesia: investigating the benefits of multiple recall tests.

Hypermnesia is an increase in recall over repeated tests. A core issue is the role of repeated testing, per se, versus total retrieval time. Prior research implies an equivalence between multiple recall tests and a single test of equal total duration, but theoretical analyses indicate otherwise. Three experiments investigated this issue using various study materials (unrelated word lists, related word lists, and a short story). In the first experimental session, the study phase was followed by a series of short recall tests or by a single, long test of equal total duration. Two days later, participants took a final recall test. The multiple and single test conditions produced equivalent performance in the first session, but the multiple test group exhibited less forgetting and fewer item losses in the final test. In a fourth experiment, using a brief delay (15 min) between the recall sessions, the multiple recall condition produced greater hypermnesia as well as fewer item losses. In addition, final recall was significantly higher in the multiple than in the single test condition in three of the four experiments. Thus, single and repeated recall tests of equal total duration are not functionally equivalent, but rather produce differences observable in subsequent recall tests.

Analysis of Variance↗

PubMed2004

Generation and memory for contextual detail.

Generation enhances item memory but may not enhance other aspects of memory. In 12 experiments, the author investigated the effect of generation on context memory, motivated in part by the hypothesis that generation produces a trade-off in encoding item and contextual information. Participants generated some study words (e.g., hot-c__) and read others (e.g., hot-cold). Generation consistently enhanced item memory but did not enhance context memory. More specifically, generation disrupted context memory for the color of the target word but did not affect context memory for location, background color, and cue-word color. The specificity of the negative generation effect in context memory argues against a general item-context trade-off. A processing account of generation meets greater success. In addition, the results provide no evidence that generation enhances recollection of contextual details.

Cues↗

PubMed2004

Memory for actions: enactment and source memory.

Enacting simple action phrases enhances item memory but may not enhance other aspects of memory. The present experiment examines the effects of enactment on source memory. During the study phase, participants performed some actions (subject-performed tasks, SPTs) and observed the experimenter perform other actions (experimenter-performed tasks, EPTs). One group performed the SPTs with eyes closed, one group with eyes open (the standard condition), and one group performed SPTs facing a mirror (EPT presentation was constant across groups). As expected, item memory was better for SPTs than for EPTs. More importantly, source memory for SPTs was affected by the amount of visual feedback. As predicted by the source-monitoring framework, source memory for SPTs decreased as the amount of visual feedback increased from none (eyes closed) to moderate (standard condition) to maximal (mirror condition). In addition, SPT encoding failed to increase source memory and in one condition actually decreased source memory, relative to EPT encoding. Thus, enactment dissociated item and source memory, enhancing the former but not the latter.

Affect↗

PubMed2003

Effects of cross-modal and intramodal division of attention on perceptual implicit memory.

Extant results motivate 3 hypotheses on the role of attention in perceptual implicit memory. The first proposes that only intramodal manipulations of attention reduce perceptual priming. The second attributes reduced priming to the effects of distractor selection operating in a central bottleneck process. The third proposes that manipulations of attention only affect priming via disrupted stimulus identification. In Experiment 1, a standard cross-modal manipulation did not disrupt priming in perceptual identification. However, when study words and distractors were presented synchronously, cross-modal and intramodal distraction reduced priming. Increasing response frequency in the distractor task produced effects of attention regardless of target-distractor synchrony. These effects generalized to a different category of distractors arguing against domain-specific interference. The results support the distractor-selection hypothesis.

Attention↗

PubMed2003

Using the analysis of covariance to increase the power of priming experiments.

Although priming paradigms are widely used in cognitive psychology, the statistical analyses typically applied to priming data may not be optimal. Conceiving of priming paradigms as change-from-baseline designs suggests that the analysis of covariance (ANCOVA), using baseline performance as the covariate, is a more efficient (i.e., powerful) analysis. Specifically, ANCOVA provides more powerful tests of 1) the presence of priming and 2) between-group differences in priming. In addition, for within-subject designs with multiple baseline conditions, ANCOVA may increase the power of within-subjects effects. Efficiency gains are demonstrated with a re-analysis of priming datasets from implicit memory research. It is suggested that similar gains may be realized in other areas of priming research. Important assumptions of this procedure, which must be evaluated for the appropriate application of ANCOVA, are discussed.

Analysis of Variance↗

PubMed2003

Long-term flashbulb memory for learning of Princess Diana's death.

Flashbulb memories are unusually vivid recollections of the circumstances in which one first learns of a shocking and emotionally arousing event. In the present study we examined students' memories concerning the death of Diana. Princess of Wales. Participants completed a standard flashbulb memory questionnaire 1 week after her death, in which they reported the circumstances in which they first heard the news. Accuracy of these memories (defined by consistency of responses across delays) was investigated by either a single retest 18 months after the event, or two retests at 3 and 18 months after the event. Participants' descriptions remained accurate at both 3 and 18 months, and testing at 3 months had no effect on accuracy of the subsequent 18-month responses. Consistent with previous research, both emotional intensity and rehearsal were related to accuracy.

Emotions↗

PubMed2003

Memory for actions: self-performed tasks and the reenactment effect.

Encoding action phrases by enactment (self-performed tasks, or SPTs) leads to better memory than does observing actions (experimenter-performed tasks, or EPTs) or hearing action phrases (Engelkamp, 1998). In addition, recognition memory for SPTs is enhanced when test items are reenacted. Experiment 1 demonstrated a reenactment effect for EPTs, as well as for SPTs, indicating that the effect can be based on visual, as well as motoric, feedback. However, the reenactment effect in SPTs was found even when the participants were blindfolded at test (Experiment 2), indicating that the basis for the reenactment effect differs across SPTs and EPTs. Experiments 3 and 4 provided additional evidence that visual feedback is not critical for reenactment recognition in the case of SPTs. In addition, these experiments failed to show a hand congruency effect (enhanced recognition when the same hand enacts at study and at test), indicating that this effect is not as generalizable as the reenactment effect. These results have important implications for the motor-encoding hypothesis of the enactment effect.

Feedback↗

PubMed2003

Inhibition and attention deficit hyperactivity disorder in adults.

The inhibitory account of attention deficit hyperactivity disorder (ADHD) was tested by examining the performance of college-aged adults on a variety of inhibitory tasks. The poorer performance of adults with ADHD compared with controls on negative priming, stopping, and continuous performance tasks, combined with similar group performances on a test of working memory capacity, indicates a specific inhibitory deficit as opposed to a general limitation in attentional capacity. Overall results provide evidence for extending the inhibitory deficit hypothesis to adult ADHD, not only for mechanisms of response (or motor) inhibition but also for mechanisms of cognitive inhibition.

Adult↗

PubMed2002

Attention and perceptual implicit memory: effects of selective versus divided attention and number of visual objects.

Extant research presents conflicting results on whether manipulations of attention during encoding affect perceptual priming. Two suggested mediating factors are type of manipulation (selective vs divided) and whether attention is manipulated across multiple objects or within a single object. Words printed in different colors (Experiment 1) or flanked by colored blocks (Experiment 2) were presented at encoding. In the full-attention condition, participants always read the word, in the unattended condition they always identified the color, and in the divided-attention conditions, participants attended to both word identity and color. Perceptual priming was assessed with perceptual identification and explicit memory with recognition. Relative to the full-attention condition, attending to color always reduced priming. Dividing attention between word identity and color, however, only disrupted priming when these attributes were presented as multiple objects (Experiment 2) but not when they were dimensions of a common object (Experiment 1). On the explicit test, manipulations of attention always affected recognition accuracy.

Attention↗

PubMed2002

Positive and negative generation effects, hypermnesia, and total recall time.

Self-generated information is typically remembered better than perceived information (the generation effect). Experimental design produces an important limiting condition for this effect: Generation enhances recall in within-subjects designs, but typically not in between-subjects designs. However, Mulligan (2001) found that the generation effect emerged over repeated recall tests in a between-subjects design, calling into question the generality of this limiting condition. Two experiments further delineated the emergent generation effect Experiment 1 demonstrated that this effect does not require multiple discrete recall tests but may emerge on a single recall test of long duration. Experiment 2 demonstrated that the negative generation effect (a reversal of the typical generation effect produced under certain conditions) is abolished by multiple recall tests. In both experiments, the generate condition produced greater hypemnesia (increased recall over tests) than did the read condition.

Affect↗

PubMed2002

The generation effect: dissociating enhanced item memory and disrupted order memory.

Generating stimuli at encoding typically improves memory for occurrence (item memory) but might disrupt memory for order. In three experiments, the relationship between generation and order memory was examined by using familiar stimuli, which give rise to the standard generation advantage in item memory, and unfamiliar stimuli, which do not. The participants generated or read words and non-words in Experiments 1 and 2 and familiar and unfamiliar word compounds in Experiment 3. For the familiar stimuli, generation enhanced item memory (as measured by recognition) but disrupted performance on the order-reconstruction test. For the unfamiliar stimuli, generation produced no recognition advantage and yet persisted in disrupting order reconstruction. Thus, the positive effects of generation on item memory were dissociated from its negative impact on order memory.

Association↗

PubMed2002

The emergence of item-specific encoding effects in between-subjects designs: perceptual interference and multiple recall tests.

The perceptual-interference effect occurs when interference with word perception (by backward masking) enhances later memory for the word. In terms of the item-specific-relational framework (Hunt & McDaniel, 1993), this effect is similar to other manipulations that enhance item-specific encoding (such as the generation effect). One similarity is that item-specific effects typically do not arise in between-subjects designs. However, the present experiment demonstrates that a between-subjects perceptual-interference effect emerges over multiple recall tests. Furthermore, perceptual interference produces both more intertest gains (indexing enhanced item-specific processing) and more intertest losses (indexing disrupted relational encoding) compared with the intact (control) condition. Finally, delaying the mask to a point at which it no longer interferes with perception (266 msec) eliminates both the perceptual-interference recall advantage and the increase in intertest gains. This condition still produces more intertest losses, however. Together, these results imply that a delayed mask disrupts relational encoding but produces no item-specific enhancement, dissociating the two effects of the perceptual-interference manipulation.

Attention↗

PubMed2002

The emergent generation effect and hypermnesia: influences of semantic and nonsemantic generation tasks.

The generation effect is moderated by experimental design, affecting recall in within-subjects designs but typically not in between-subjects designs. However, N. W. Mulligan (2001) found that the generation effect emerged over repeated recall tests in a between-subjects design, calling into question the generality of this limiting condition. In addition, the generate condition but not the read condition produced hypermnesia (increased recall over tests). The present experiments demonstrate that semantic-based (semantic-associate and category-associate) generation tasks produce this pattern of results whereas nonsemantic (letter transposition, rhyme, word fragment) generation tasks do not. Thus, the emergent generation effect appears to be a byproduct of semantic elaboration rather than a direct product of generation. In addition, high- and low-imagery words produced equivalent hypermnesia and emergent generation effects, arguing against a mediating role for imagistic encoding. Finally, there is no evidence of an emergent generation effect for nonwords, another traditional limiting condition of the generation effect.

Attention↗