The effects of autobiographical memory and visual perspective on working memory

The present research aims to explore whether recalling and writing about autobiographical memory from different perspectives (first-person perspective vs. third-person perspective) could affect cognitive function. The participants first performed a working memory task to evaluate their working memory capacity as a baseline and then were instructed to recall (Study 1) or write about (Study 2) personal events (failures vs. successes) from the first-person perspective or the third-person perspective. Finally, they performed the working memory task again. The results suggested that autobiographical memory and perspective influence working memory interactively. When recalling a success, the participants who recalled from the third-person perspective performed better than those who recalled from the first-person perspective on the working memory capacity task; when recalling a failure, the opposite was true.     

The effects of elaboration on recognition memory

Two experiments were conducted to examine the effects of elaboration on recognition memory. Subjects were given either simple or complex sentences to learn and were tested for recognition of either an individual target word or the entire sentence. Complex sentences supported better recognition performance only when the test item allowed the subject to easily redintegrate the initial encoding context, either by re-presenting the encoded sentence as the test item or by constructing sentences such that the component words of the sentence could be easily redintegrated from an individual target item. It was suggested that complex, elaborate encoding established a richer trace, but that this richness can be utilized to enhance recognition only when the test conditions permit a reinstatement of the original encoding context.     

The effects of generation on auditory implicit memory

The generation manipulation produces the classic functional dissociation between explicit and implicit memory. This dissociation has been explained by the transfer-appropriate processing (TAP) framework, which emphasizes the overlap in cognitive processes operative at encoding and at retrieval. However, the vast majority of implicit memory studies have been conducted in the visual modality; in the auditory modality, the effects of generation have never been investigated. In four experiments, we examined the effects of generating from semantic and nonsemantic cues on auditory implicit tests. Generating from antonyms produced a reversed generation effect on priming in auditory perceptual identification and word stem completion, while producing the traditional positive effect on explicit recognition. Generating from definitions, as well as from rhymes, also produced a reversed generation effect on auditory priming. These results are critical for more fully characterizing auditory priming and are consistent with an extended TAP analysis.     

The obligatory effects of memory on eye movements

Previous work has shown that eye movement behaviour is affected by previous experience, such that alterations in viewing patterns can be observed to previously viewed compared to novel displays. The current work addresses the extent to which such effects of memory on eye movement behaviour are obligatory; that is, we examined whether prior experience could alter subsequent eye movement behaviour under a variety of testing conditions, for stimuli that varied on the nature of the prior exposure. While task demands influenced whether viewing was predominantly directed to the novel versus familiar faces, viewing of the familiar faces was distinguished from viewing of the novel faces, regardless of whether the task required incidental encoding or intentional retrieval. Changes in scanning of previously viewed over novel faces emerged early in viewing; in particular, viewing duration of the first fixation to the familiar faces was often significantly different from the duration of the first fixation directed to the novel faces, regardless of whether prior exposure was solely in the context of the experiment or due to real-world exposure. These findings suggest that representations maintained in memory may be retrieved and compared with presented information obligatorily.     

The effects of unvocalized music on short-term memory

The studies reported here investigated the role of background music in verbal processing. The experiment was a partial replication of Salame and Baddeley (1989), where the effect of music on the recall of digits, was examined, but included an additional key condition where participants heard instrumental music without the words usually associated with it. In this case we used nursery rhymes. In addition, articulatory suppression was manipulated as a tool to look at the role of working memory in the task. The relationship between long-term memory and working memory was further explored by using an implicit memory task to examine verbal memory effects for words associated with the music but not actually heard. The results indicated that background, instrumental music, long-associated with words, significantly impairs concurrent verbal processing. These long-term memory effects on working memory were, however, not associated with implicit memory effects, and no priming was observed.     

The effects of bilateral ECT on primary memory

Sixteen patients treated with bilateral ECT and sixteen students were tested with single-trial free recall. Testing was carried out at both a fast and a slow rate of presentation, and recall was either immediate or delayed for 30 sec. The primary memory component was estimated with five different methods, and it is concluded that this memory component is essentially unaffected by ECT. The results are discussed in relation to other studies showing that individual differences in memory capacity are primarily related to the secondary memory component. It is argued that the results obtained in studies of memory functions in ECT patients and in patients with chronic amnesic syndromes are similar. The normal primary memory component in ECT patients is not considered conclusive evidence of two storage systems.     

The effects of unvocalized music on short-term memory

The studies reported here investigated the role of background music in verbal processing. The experiment was a partial replication of Salame and Baddeley (1989), where the effect of music on the recall of digits, was examined, but included an additional key condition where participants heard instrumental music without the words usually associated with it. In this case we used nursery rhymes. In addition, articulatory suppression was manipulated as a tool to look at the role of working memory in the task. The relationship between long-term memory and working memory was further explored by using an implicit memory task to examine verbal memory effects for words associated with the music but not actually heard. The results indicated that background, instrumental music, long-associated with words, significantly impairs concurrent verbal processing. These long-term memory effects on working memory were, however, not associated with implicit memory effects, and no priming was observed.     

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.     

The effects of eye and limb movements on working memory

Three experiments examined the role of eye and limb movements in the maintenance of information in spatial working memory. In Experiment 1, reflexive saccades interfered with memory span for spatial locations but did not interfere with memory span for letters. In Experiment 2, three different types of eye movements (reflexive saccades, pro-saccades, and anti-saccades) interfered with working memory to the same extent. In all three cases, spatial working memory was much more affected than verbal working memory. The results of these two experiments suggest that eye movements interfere with spatial working memory primarily by disrupting processes localised in the visuospatial sketchpad. In Experiment 3, limb movements performed while maintaining fixation produced as much interference with spatial working memory as reflexive saccades. These results suggest that the interference produced by eye movements is not the result of their visual consequences. Rather, all spatially directed movements appear to have similar effects on visuospatial working memory.     

The effects of prior knowledge on children's memory and suggestibility

In this study, 5- and 6-year-olds were read a story and asked to recall its details. Two independent factors-prestory knowledge and poststory suggestions-were crossed to examine the effects on children's story recall. The results indicated that prestory social knowledge about the story protagonist as well as academic knowledge relating to the content of the story influenced the accuracy of children's recall immediately after the story presentation. Following the suggestive interview, children reported interviewer-provided social and academic misinformation to a greater extent when the misinformation was consistent with their prior knowledge. In contrast, children were more likely to refute misinformation that contradicted their academic knowledge. These findings are discussed in terms of the mechanisms underlying the knowledge-memory and knowledge-suggestibility linkages.     

The effects of emotion and encoding strategy on associative memory

Research has demonstrated that when discrete pieces of information are integrated together at encoding-imagining two items together as a single entity, for example-there is a mnemonic benefit for their relationship. A separate body of literature has indicated that the presence of emotional information can have an impact on the binding of associated neutral details, in some cases facilitating associative binding (MacKay et al. Memory and Cognition 32:474-488, 2004; Mather, Perspectives on Psychological Science 2:33-52, 2007), and in other cases impeding the processing of associated details (Easterbrook, Psychological Review 66:183-201, 1959; Kensinger, Emotion Review 1:99-113, 2009). In the present experiments, we investigated how memory for neutral words is affected by the emotionality of the information with which they are presented (whether with an emotional word or a second neutral word) and the encoding context (integrated or nonintegrated strategy). Participants viewed word pairs and were instructed to visualize the items as an integrated unit or to visualize them separately from one another. The results of Experiment 1 showed a disproportionate mnemonic benefit for neutral items that were integrated with other neutral items over those integrated with emotional items. The results of Experiments 2A and 2B showed that this effect interacted with encoding time: When given 2?s to encode, participants showed no effect of integration on memory for neutral-neutral pairs, but showed a significant mnemonic benefit for integrating emotional-neutral pairs. When given 4 or 6?s, the integrative benefit increased significantly for neutral-neutral pairs but decreased for emotional-neutral pairs. These results suggest that creating an integrated mental image of two neutral items requires a more time-consuming process than integrating an emotional and a neutral item, but that extra effort may result in a downstream mnemonic benefit.     

The effects of memory load and delay on facial recognition

This experiment examined the effects of memory load over three periods of delay. Following presentation of 20, 35, or 50 targets, subjects were required to select these from an equal number of distractors 10 min, 1 week, or 2 weeks later. Increased target load (independent of increases in recognition load) decreased accuracy mainly by decreasing hit rate. Increasing delay decreased accuracy largely as a result of an increased false alarm rate. Most individual ROC curves, plotted on z-coordinates, had slopes < 1. Implications of this finding for the use of d' are discussed.