Generation effects with nonwords: The role of test appropriateness.

Assessed the role of test appropriateness by studying generation effects with nonwords in 2 experiments, using 96 undergraduates. In Exp I, which used the switching of 2 letters as the generate task, Ss showed better memory for generated nonwords when the retention test assessed memory for which letters had been switched; in Exp II, a generation effect for nonwords emerged when Ss were required to generate items again at test, prior to the recognition decision. Results demonstrate that a robust generation effect can occur with meaningless items, as long as retention tests show sensitivity to what Ss actually generate in the nonword case. It is suggested that to allow for a generation effect to emerge, it is necessary to match what is actually generated with what is tested in the retention environment. (26 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Categorization processes in mental comparisons.

Five experiments explore categorization and category-based congruity effects in mental comparisons. The first 4 experiments concentrate on categorization of infinite-set small items. The experiments vary the additional items presented and whether those items appear once (Experiments 1-2) or repeatedly (Experiments 3-4). Additional items include other small items (Experiment 1), relatively large items (Experiments 2-4), and items involving nonsize dimensions (Experiment 4). The critical small items show a complete congruity effect only in Experiments 1 and 3. Results suggest that categorization of infinite-set items may be based on range information alone (Experiment 1) but that multiple categorizations based on multiple ranges (Experiment 2) may require attentional effort. Results implicate categorization as a central process in mental comparison, despite differences in ease of categorization across paradigm. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Generative processing and false memories: When there is no cost.

Encoding manipulations (e.g., levels of processing) that facilitate retention often result in greater numbers of false memories, a pattern referred to as the more is less effect (M. P. Toglia, J. S. Neuschatz, & K. A. Goodwin, 1999). The present experiments explored false memories under generative processing. In Experiments 1-3, using Deese-Roediger-McDermott (DRM) lists with items that were either read or generated, the authors found recognition and recall tests indicated generation effects for true memories but no increases in false memories (i.e., generation at no cost). In Experiment 4, in a departure from the DRM methodology, a cuing procedure resulted in a more is less pattern for congruous generation, and a no cost pattern for incongruous generation. This highlights the critical distinction between these encoding contexts. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Visual list memory in capuchin monkeys (Cebus apella).

Memory of 3 capuchin monkeys, Cebus apella, was tested with lists of 4 travel-slide pictures and different retention intervals. They touched different areas of a video monitor to indicate whether a test picture was in a list. At short retention intervals (0 s, 1 s, 2 s), memory was good for the last list items (recency effect). At a 10-s retention interval, memory improved for 1st list items (primacy effect). At long retention intervals (20 s and 30 s), primacy effects were strong and recency effects had dissipated. The pattern of retention-interval changes was similar to rhesus monkeys, humans, and pigeons. The time course of recency dissipation was similar to rhesus monkeys. The capuchin's superior tool-use ability was discussed in relation to whether it reflects a superior general cognitive ability, such as memory. In terms of visual memory, capuchin monkeys were not shown to be superior to rhesus monkeys. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

What causes the isolation effect?

Events that are incongruent with their prevailing context are usually very well remembered. This fact often is described as the distinctiveness effect in memory, an effect that has served as explanation not only of memory phenomena but also of various other phenomena, including social judgment. The core laboratory paradigm for studying distinctiveness in memory research has long been the isolation paradigm. This paradigm, sometimes attributed to H. von Restorff (1933), yields better memory for an item categorically isolated from surrounding items than for the surrounding items and a proper control item. The authors offer an interpretation of the isolation effect based on the analysis of the processing of similarities and differences among the items. Two experiments provide evidence for this interpretation. The results are discussed in the context of current theories of distinctiveness effects in memory. An appeal is made for a different conceptualization of distinctiveness effects, one that treats distinctiveness as a discriminative process in memory that requires processing of both similarities and differences among items. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Detecting memory impairment with a modified test procedure: Manipulating retention interval with centrally presented event items.

Suggests that detecting memory impairment with the modified test relies on long retention intervals that provide the necessary forgetting of event information for impairing effects of postevent misinformation to occur. 288 Ss were tested in 4 experiments that presented event items centrally, introduced verbal postevent items to a misled condition, and used the modified test, but differed by using either short (15 min) or long (5–7 days) retention intervals. As evidenced by poorer misled than control test performances, memory impairment only occurred with long retention intervals. Retrieval- and storage-based versions of memory-impairment hypotheses are assessed. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

The mnemonic value of perceptual identification.

In four experiments, subjects were required to name words presented on a CRT screen. On generate trials, the words were presented quickly, at a point where roughly half could be identified correctly; on read trials, the items were presented for a full second, allowing for rapid and easy naming. A surprise recognition test for the presented items then revealed a substantial retention advantage for the briefly presented items, but no similar advantage was produced in recall. It is argued that under rapid viewing conditions subjects may fail to extract enough visual features to allow for immediate resolution, requiring the initiation of a kind of data-driven generation process. This latter process then produces a generation effect for the briefly presented items compared with the read items, but only on a retention test that shows sensitivity to data-driven processing. These results are discussed from the standpoint of current theoretical views on the generation effect. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Enhancing effects of similarity on long-term memory for order.

Four incidental learning experiments examined the effects of stimulus similarity on long-term memory for order. Although most current theories of order retention easily handle, and often predict, a disruption in order retention under conditions of high intralist similarity, the opposite result, an enhancing effect of similarity, presents a significant interpretive puzzle. All 4 of the present experiments demonstrate conditions in which phonological or categorical similarity significantly improves both absolute and relative long-term memory for sequential order. Tentative interpretations of these results are provided, on the basis of list discrimination arguments and the operation of study–phase reminding processes. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Short-term memory in autism spectrum disorder.

Three experiments examined verbal short-term memory in comparison and autism spectrum disorder (ASD) participants. Experiment 1 involved forward and backward digit recall. Experiment 2 used a standard immediate serial recall task where, contrary to the digit-span task, items (words) were not repeated from list to list. Hence, this task called more heavily on item memory. Experiment 3 tested short-term order memory with an order recognition test: Each word list was repeated with or without the position of 2 adjacent items swapped. The ASD group showed poorer performance in all 3 experiments. Experiments 1 and 2 showed that group differences were due to memory for the order of the items, not to memory for the items themselves. Confirming these findings, the results of Experiment 3 showed that the ASD group had more difficulty detecting a change in the temporal sequence of the items. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

A central capacity limit to the simultaneous storage of visual and auditory arrays in working memory.

If working memory is limited by central capacity (e.g., the focus of attention; N. Cowan, 2001), then storage limits for information in a single modality should apply also to the simultaneous storage of information from different modalities. The authors investigated this by combining a visual-array comparison task with a novel auditory-array comparison task in 5 experiments. Participants were to remember only the visual, only the auditory (unimodal memory conditions), or both arrays (bimodal memory conditions). Experiments 1 and 2 showed significant dual-task tradeoffs for visual but not for auditory capacity. In Experiments 3-5, the authors eliminated modality-specific memory by using postperceptual masks. Dual-task costs occurred for both modalities, and the number of auditory and visual items remembered together was no more than the higher of the unimodal capacities (visual: 3-4 items). The findings suggest a central capacity supplemented by modality- or code-specific storage and point to avenues for further research on the role of processing in central storage. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Spatial memory for food hidden by rats (Rattus norvegicus) on the radial maze: Studies of memory for where, what, and when.

Rats (Rattus norvegicus) were allowed to hide food items on an 8-arm radial maze by carrying the items from the center to boxes at the end of each arm. Retrieval tests given after rats had hidden 4 items showed that they selectively returned to the maze arms where food had been hidden (Experiments 1 and 2). When rats were allowed to hide pieces of cheese (preferred food) and pretzels (less preferred food) on different arms, they both hid and retrieved cheese before pretzels (Experiments 2-5). In Experiment 6, rats chose between arms where cheese and pretzels were hidden, with cheese degraded at one delay interval but not the other. Together, these experiments indicate memory for what and where but not when. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Working memory and changing-state hypothesis.

Effects of secondary tasks on serial short-term memory were investigated to test conflicting predictions derived from the working-memory model (A. D. Baddeley, 1986, 1997) and the changing-state hypothesis (D. M. Jones, P. Farrand, G. Stuart, & N. Morris, 1995). In Experiments 1 and 2, disruptions due to the changing-state characteristic of secondary tasks occurred in the encoding phase of spatial and verbal serial memory tasks but not in a retention interval. Experiments 3 and 4 revealed changing-state effects on tasks relying on central-executive resources. In Experiments 5 and 6, interference between central-executive demanding secondary tasks and serial short-term memory was larger during the encoding phase than the retention interval. Crossover dissociations emerged between spatial and verbal serial short-term memory. The results extend the findings of D. M. Jones et al. (1995) and support the working-memory account for interference in short-term memory. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Generation effects in frequency judgment.

The generation effect is the advantage in memory for information that is self-produced, rather than read. Seven experiments studied this effect on tasks requiring memory for frequency of occurrence. Generation effects were found on both relative and absolute frequency judgment and for both rhyming and letter-switching generation tasks. No generation effect was found on items at the lowest true frequency, when repetitions were massed, when nonwords were used as stimuli, or when subjects were given accurate frequency information during list presentation. These results are discussed in terms of a multiple-trace account of frequency information. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Multiple roles for time in short-term memory: Evidence from serial recall of order and timing.

Three experiments are reported that examine the relationship between short-term memory for time and order information, and the more specific claim that order memory is driven by a timing signal. Participants were presented with digits spaced irregularly in time and postcued (Experiments 1 and 2) or precued (Experiment 3) to recall the order or timing of the digits. The primary results of interest were as follows: (a) Instructing participants to group lists had similar effects on serial and timing recall in inducing a pause in recall between suggested groups; (b) the timing of recall was predicted by the timing of the input lists in both serial recall and timing recall; and (c) when the recall task was precued, there was a tendency for temporally isolated items to be more accurately recalled than temporally crowded items. The results place constraints on models of serial recall that assume a timing signal generates positional representations and suggest an additional role for information about individual durations in short-term memory. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Assessing the inhibitory account of retrieval-induced forgetting with implicit-memory tests.

Five experiments examined whether retrieval-induced-forgetting effects are observed for implicit tests of memory. In each experiment participants first studied category- exemplar paired associates, then practiced retrieval for a subset of items from a subset of categories before finally completing memory tests for all the studied items. In standard fashion, inhibition was measured as the performance difference of unpracticed items from practiced categories and unpracticed items from unpracticed categories. Across the 5 experiments poorer performance for unpracticed items was seen in conceptual implicit memory (category generation and category matching) but not in perceptual implicit memory (stem completion, perceptual identification). Thus, retrieval-induced-forgetting effects are limited to tests of conceptual memory. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Cue distinctiveness and forgetting: Effectiveness of self-generated retrieval cues in delayed recall.

Determinants of cue-dependent forgetting were examined in four experiments. The variability in meaning of retrieval cues was proposed as one central factor underlying cue-dependent forgetting. The results of Experiment 1 demonstrated that the instructions to the subjects to focus their generation on certain distinctive properties of the target items reduced the variability in meaning of the generated cues. Experiment 2 revealed that the properties generated under these instructions served as very effective cues after retention intervals up to 6 weeks. Experiments 3 and 4 demonstrated that the rate of forgetting was significantly lower when distinctive, in contrast to nondistinctive, retrieval cues were provided at delayed tests. Cue distinctiveness was proposed as an alternative to the traditional context-reinstatement approach for optimizing cue–trace compatibility. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

The negative suggestion effect: Pondering incorrect alternatives may be hazardous to your knowledge.

This article examines the negative suggestion effect, or the impact of exposure to incorrect alternatives on memory for correct information. All experiments used the following design: (a) cued-recall test of general facts (e.g., "second smallest planet") with immediate correct feedback, (b) interpolated exposure to incorrect information related to Test 1 items, and (c) a second test over the same items as Test 1. Test 2 was either multiple choice or cued recall and was given either immediately or 1 week after interpolation. Three experiments confirmed the existence of negative suggestion: Exposure to misinformation hindered subsequent performance on those items, relative to noninterpolated control items. The magnitude of this decrement is unrelated to retention interval, type of second test, number of incorrect alternatives exposed, and number of repetitions of incorrect alternatives. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

The generation effect: A test between single- and multifactor theories.

Single- and multifactor accounts of the generation effect (better memory for internally generated items than for externally presented items) were tested. Single-factor theories suggest that generation induces either stimulus–response relational processing or response-oriented processing. Multifactor theories suggest that generation induces both types of processing. In the first 3 experiments Ss either read or generated responses, and the degree of categorical structure within the list was manipulated. When categorical structure was minimal, large generation effects were observed for free recall and recognition, but not for cued recall. When categorical structure was high, however, a generation effect was observed for cued recall but not for recognition or free recall. A 4th experiment was performed to eliminate an uninteresting interpretation of the results. It is argued that a multifactor account is needed to explain these findings. (PsycINFO Database Record (c) 2011 APA, all rights reserved)     

A recency-based account of the primacy effect in free recall.

Seven experiments investigated the role of rehearsal in free recall to determine whether accounts of recency effects based on the ratio rule could be extended to provide an account of primacy effects based on the number, distribution, and recency of the rehearsals of the study items. Primacy items were rehearsed more often and further toward the end of the list than middle items, particularly with a slow presentation rate (Experiment 1) and with high-frequency words (Experiment 2). Recency, but not primacy, was reduced by a filled delay (Experiment 3), although significant recency survived a filled retention interval when a fixed-rehearsal strategy was used (Experiment 4). Experimenter-presented schedules of rehearsals resulted in similar serial position curves to those observed with participant generated rehearsals (Experiment 5) and were used to confirm the main findings in Experiments 6 and 7. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Turning simple span into complex span: Time for decay or interference from distractors?

We investigated the effects of the duration and type of to-be-articulated distractors during encoding of a verbal list into short-term memory (STM). Distractors and to-be-remembered items alternated during list presentation, as in the complex-span task that underlies much of working-memory research. According to an interference model of STM, known as serial order in a box (SOB; Farrell & Lewandowsky, 2002), additional repeated articulations of the same word between list items should cause minimal further disruption of encoding into STM even though the retention interval for early list items is increased. SOB also predicts that the articulation of several different distractor items should lead to much enhanced disruption if the distractor interval is increased. Those predictions were qualitatively confirmed in 4 experiments that found that it is the type of distractors, not their total duration, that determines the success of encoding a list into STM. The results pose a challenge to temporal models of complex-span performance, such as the time-based resource sharing model (Barrouillet, Bernardin, & Camos, 2004). The results add to a growing body of evidence that memory for the short term is not exclusively governed by purely temporal processes. (PsycINFO Database Record (c) 2010 APA, all rights reserved)