Word Fragment Research Articles

Role of the Frontal Lobes in Implicit and Explicit Retrieval Tasks

While the role of the frontal lobes in explicit retrieval tasks is well supported, the findings for implicit tasks are less conclusive. We investigated the role of the frontal lobes in perceptual and conceptual implicit priming. Three memory paradigms were given under both implicit and explicit retrieval instructions, using word fragment completion, picture fragment completion and category exemplar generation. Three groups of individuals with frontal lesions were compared to normal controls: Left dorsolateral lesions (n = 5), right dorsolateral lesions (n = 4), and medial lesions (n = 9). Word fragment completion priming was impaired by left dorsolateral lesions, with other priming tests unaffected by any lesion. Explicit performance showed a different pattern, with category exemplar cued recall impaired by left dorsolateral and medial lesions. These findings support the role of the frontal lobes in both implicit and explicit retrieval mechanisms under certain conditions requiring strategy application or lexical retrieval.

Further evidence of preserved priming and impaired recall in adults with Asperger's syndrome.

Two experiments compared incidental (implicit) and intentional (explicit) memory performance in adults with Asperger's syndrome and individually matched controls. Experiment 1 involved perceptual tests using word fragment cues, following study tasks in which the participants either generated the words from contextual cues or read the words alone, with no contextual cues. Experiment 2 involved conceptual tests using paired associate cues, following study tasks in which the paired associates were rated either for their relatedness or for their readability. Performance in both the incidental tests was similar for both groups. Performance in both the intentional tests was also similar for both groups, with one exception. The adults with Asperger's syndrome were more likely to falsely recall words that had not actually been studied. These findings further delimit the nature of memory impairments in adults with Asperger's syndrome, which seem restricted to certain aspects of episodic memory that include the tendency to make more intrusion errors in recall.

More on magnitude of priming in implicit memory tasks.

The effects of word frequency, length of the word, and type of word fragment in a fragment-completion test were investigated with 57 undergraduate students, 19-22 years. Priming with better performance on studied than on nonstudied words in this task was greater for low frequency words than for high frequency words and greater for fragments without the first letter than for fragments with the first letter. It was inferred that characteristics of fragments should be considered in any implicit memory task when the magnitude of priming is of interest. In general, word fragment-completion processes appear to be based on sources of information available in visual identification tasks.

Bias effects in word fragment completion in young and older adults

Young and older adults were tested on a word fragment completion task in which correct solutions were studied words, words orthographically similar to studied words, or new words. In Experiments 1 and 2, the standard production version of the word fragment completion task was used; older adults had reduced benefits of prior exposure to target words and slightly decreased costs. However, costs and benefits did not differ across age in a forced-choice version of the task (Experiment 3). At a behavioral level, the results are contrary to predictions that age differences in word fragment completion priming effects will be greater when there is a strong competitor for the correct solution and that age differences in both costs and benefits will be smaller for identification than for production tasks. Theoretical implications of these findings are considered.

Dissociating perceptual and conceptual implicit memory in multiple sclerosis patients

Previous studies indicate that Multiple Sclerosis (MS) patients exhibit deficits in tests of explicit memory such as free recall, but show normal priming on implicit tests of memory such as word stem completion. However, the memory performance of patients with different MS disease subtypes has not been fully examined. In the current study, memory was assessed in Primary Progressive (PPMS), Relapsing Remitting (RRMS), and Secondary Progressive (SPMS) MS subgroups. Explicit memory as well as perceptual and conceptual implicit memory were examined using free recall, word fragment completion, and exemplar generation tests, respectively. All three groups of MS patients exhibited free recall deficits and normal priming on the exemplar generation test. However, the PPMS group exhibited a deficit in word fragment completion priming, whereas the RRMS and SPMS groups exhibited normal levels of priming on this task. Lesion load was assessed using magnetic resonance imaging and was negatively correlated with explicit memory performance, but it did not account for the observed deficits in perceptual implicit memory. The results indicate that PPMS patients exhibit a pattern of memory impairment that is distinct from that of the RRMS and SPMS groups. Moreover, the results indicate that perceptual implicit memory can be neurologically dissociated from conceptual implicit memory.

The orthographic distinctiveness effect on direct and indirect tests of memory: delineating the awareness and processing requirements

We examined the processing and awareness requirements that mediate superior memory for distinct items in long-term memory by studying the effects of orthographic distinctiveness. Orthographically distinct words are remembered better than common words on the direct test of free recall but not on the indirect test of perceptual identification. These results suggest that the orthographic distinctiveness effect requires test awareness. But interestingly, this distinctiveness effect has also been reported in one indirect test, that of word fragment completion ( Hunt & Toth, 1990). We examined the locus of the orthographic distinctiveness effect in the indirect test of word fragment completion and the direct tests of word fragment cued recall and free recall and assessed the role of awareness (Experiment 1) and conceptual processes (Experiments 2a–2c) in mediating this effect. Our results support the proposal that the distinctiveness effect depends on direct reference to the study context and further specify that this effect is mediated, to a large extent, by comparative processes even when distinctiveness emerges from surface-level differences.

Recognition with and without identification: dissociative effects of meaningful encoding.

In a series of four experiments, the effects of levels of processing and generation on the recognition of identified versus unidentified word fragments were examined. After studying a list of words, participants took a word fragment completion test in which half of the fragments came from studied words and half came from nonstudied words. Regardless of whether they could complete a given fragment, the participants were asked to rate the likelihood that it came from a studied word. Recognition of identified fragments was best whenever the focus of the encoding task was on meaning. Recognition of unidentified fragments did not benefit from meaningful encoding in any of the experiments reported here but did benefit from generation. It is suggested that whereas recognition with identification involves the use of meaning, recognition without identification involves the use of abstract orthographic information in memory.

The role of state self‐esteem in positive mood effects on person impression: When does a positive mood lead to a favorable view of others?

Abstract:Subjects in a positive or a neutral mood were engaged in an impression formation task (Experiment 1), and in a word fragment completion task (Experiment 2). A self‐referent versus other‐referent sentence completion task was used to induce a positive mood state. As a result, the subjects exhibited mood congruent effects on impression ratings in the self‐referent but not in the other‐referent mood induction condition. Word completion data, however, indicated that relevant traits (i.e., friendly traits) had been equally activated across the two mood induction conditions. It was also demonstrated that the self‐referent induction procedure was effective in enhancing the level of self‐esteem, whereas the other‐referent one was not. The results converged to suggest that the enhancement in state self‐esteem accompanying the self‐referent procedure might be relevant to positive mood effects on person impression. This indicates the limitation of the mood priming model.

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.

State Self-Esteem as a Moderator of Negative Mood Effects on Person Impression

Participants in a negative or a neutral mood performed an impression formation task in Experiment 1, a word fragment completion task in Experiment 2, and both tasks in Experiment 3. A self-referent versus other-referent sentence completion task was used to induce a negative mood. As a result, participants exhibited fewer mood-congruent effects on impression rating in the self-referent than in the other-referent mood induction condition, even though relevant traits had been equally activated across the two conditions. It was also shown that the self-referent induction procedure was accompanied by degrading of self-esteem, whereas the other-referent one was not. Taken together, the results suggest that the state self-esteem might be relevant to moderating of the negative mood effects on person impression.

MORE ON MAGNITUDE OF PRIMING IN IMPLICIT MEMORY TASKS

The effects of word frequency, length of the word, and type of word Fragment in a fragment-completion test were investigated with 57 undergraduate students, 19–22 years. Priming with better performance on studied than on nonstudied words in this task was greater for low frequency words than for high frequency words and greater for fragments without the first letter than for fragments with the first letter. It was inferred that characteristics of fragments should be considered in any implicit memory task when the magnitude of priming is of interest. In general, word fragment-completion processes appear to be based on sources of information available in visual identification tasks.

Successive Memory Test Performance and Priming in Alzheimer's Disease: Evidence from the Word-Fragment Completion Task

This study assessed the performance of patients with Alzheimer's disease and healthy controls in a successive memory test paradigm. Subjects studied lists of words. Following study, tests of recognition (an explicit memory task) and primed word fragment completion (an implicit memory task) were administered. Since the same words were used in the two tasks, we were able to calculate the degree of dependence between recognition performance and primed word fragment completion. AD patients evidenced impaired recognition memory. In contrast, priming was intact. The pattern of correlation between the two tasks was similar in healthy controls and in AD. Independence between recognition and fragment completion was obtained when recognition preceded the fragment completion task, but not when fragment completion preceded recognition.

Form-Specific Visual Priming in the Left and Right Hemispheres

Word fragment completion performance was examined for items that were presented in the same or different letter case at study and test. During the study phase words and nonwords were presented at central fixation, then during the test phase a divided visual field technique was used in which word fragments were presented briefly to the right hemisphere (left visual field) or the left hemisphere (right visual field). Previous research using the word stem completion task indicated that only the right hemisphere was sensitive to case changes in words from study to test. In contrast, the current results indicate that in the fragment completion task the priming effects for the test items presented to either hemisphere were greater when the fragments were in the same compared to different letter case at study and test. These results indicate that both hemispheres are capable of supporting form-specific visual implicit memory.

A Comparison of Forgetting for Conscious and Automatic Memory Processes in Word Fragment Completion Tasks

Differential forgetting rates have been used as one argument for separable memory systems for implicit and explicit memory. In a previous study (McBride & Dosher, 1997), however, stem completion performance showed similar forgetting rates for both implicit and explicit instructions. The current study evaluated forgetting for implicit and explicit word-fragment completion. In Experiment 1, forgetting rates were compared for implicit and explicit task performance. Forgetting rates did not differ significantly between the two tasks. In Experiment 2, conscious and automatic memory estimates derived from multinomial models for process dissociation were compared. Forgetting rates for conscious and automatic memory processes did not differ significantly when estimated by a Jacoby equation-based model or by a guessing-elaborated model. Results indicate that forgetting is similar for conscious and automatic memory processes when measured with a fragment completion task for delays up to 45 min.

Segmental and Suprasegmental Mismatch in Lexical Access

Four cross-modal priming experiments in Spanish addressed the role of suprasegmental and segmental information in the activation of spoken words. Listeners heard neutral sentences ending with word fragments (e.g., princi-) and made lexical decisions on letter strings presented at fragment offset. Responses were compared for fragment primes that fully matched the spoken form of the initial portion of target words, versus primes that mismatched in a single element (stress pattern; one vowel; one consonant), versus control primes. Fully matching primes always facilitated lexical decision responses, in comparison to the control condition, while mismatching primes always produced inhibition. The respective strength of the contribution of stress, vowel, and consonant (one feature mismatch or more) information did not differ statistically. The results support a model of spoken-word recognition involving automatic activation of word forms and competition between activated words, in which the activation process is sensitive to all acoustic information relevant to the language's phonology.

The effects of attention on perceptual implicit memory

Reports on the effects of dividing attention at study on subsequent perceptual priming suggest that perceptual priming is generally unaffected by attentional manipulations as long as word identity is processed. We tested this hypothesis in three experiments by using the implicit word fragment completion and word stem completion tasks. Division of attention was instantiated with the Stroop task in order to ensure the processing of word identity even when the participant's attention was directed to a stimulus attribute other than the word itself. Under these conditions, we found that even though perceptual priming was significant, it was significantly reduced in magnitude. A stem cued recall test in Experiment 2 confirmed a more deleterious effect of divided attention on explicit memory. Taken together, our findings delineate the relative contributions of perceptual analysis and attentional processes in mediating perceptual priming on two ubiquitously used tasks of word fragment completion and word stem completion.

They Put Me in the Mix

They Put Me in the Mix

The revelation effect in frequency judgment.

In three experiments, we explored the revelation effect in a frequency judgment task. Participants estimated the frequency of words that had been presented one, two, four, or eight times. At test, half the words were revealed by completing word fragments, and half were presented intact. Estimated frequencies were reliably higher for revealed than for intact words, and in two of the three experiments, the revelation effect became larger as actual frequency increased. A revelation effect was obtained whether the revealed word was the same as (Experiment 1) or different from (Experiment 2) the word judged for frequency. Frequency estimates were higher for more distorted test items (Experiment 3).

Effects of dividing attention on the memory-block effect.

S. M. Smith and D. R. Tindell (1997) reported that prior study of words that are orthographically similar to the solutions of test word fragments (e.g., studying ANALOGY and completing the fragment A_L _ _GY, whose solution is ALLERGY) reduced the fragment completion rate relative to a baseline condition in which unrelated words were studied. They called this effect the memory-block effect. In the present experiment, the authors replicated this effect using a larger set of materials than that used by S. M. Smith and D. R. Tindell. The authors also found that dividing attention at study eliminated the memory-block effect. This pattern mimicked the effect of dividing attention on recognition memory but differed from the effect on repetition priming effects. The authors suggest that the memory-block effect is driven by a mechanism different from that responsible for producing repetition priming effects in an implicit fragment completion test.

The Concreteness Effect in Implicit and Explicit Memory Tests

Four experiments were conducted to examine the concreteness effect in implicit and explicit memory measures. Experiment 1 replicated prior reports of an imagery effect on an implicit conceptual memory test. In Experiment 2, we confirmed our prediction of conceptual sensitivity of free recall, explicit general knowledge, explicit word fragment completion, and the implicit general knowledge tests with a levels of processing manipulation. Furthermore, although we obtained the concreteness effect (better memory for concrete than abstract nouns) in free recall and the explicit general knowledge test, we failed to find this effect in the implicit general knowledge test. Experiment 3 revealed that the failure to find the concreteness effect on the implicit general knowledge test was not attributable to combining two encoding manipulations in Experiment 2. In Experiment 4, we ruled out the possibility that the failure to find the concreteness effect in conceptual implicit memory may be related to the number of meaningful associates for targets. We discuss the implications of these findings within the context of the transfer appropriate processing framework (Roediger, Weldon, & Challis, 1989) and the dual-code hypothesis (Paivio, 1971, 1991) of memory.