Storage and retrieval of serial‐order information

In this paper I will first review some seminal work by Conrad on the storage and retrieval of serial‐order information which is still very relevant today. Then I will discuss the TODAM (theory of distributed associative memory) approach to serial‐order effects. I will compare the three TODAM serial‐order models (the chaining model, the chunking model and the power‐set model; Murdock, 1995) but concentrate on the power set model. Its original problems can be solved, but a revised and augmented version has some new problems. This paper is more of a progress report than a finished product, so the reader should be prepared to follow the twists and turns of the argument.     

When and why is ease of retrieval informative?

In two experiments, we examined when and why ease of retrieval of information from memory affects behavioral frequency and attitudinal judgments. Overall, the results suggest that when the subjective experience of ease of retrieval is consistent with the expected ease of retrieval, the content of the information retrieved is used to make judgments. However, when there is a discrepancy between experienced and expected ease of retrieval, the subjective experience of ease of retrieval is used to make judgments. Ease of retrieval is more informative when the discrepancy between experienced and expected ease of retrieval cannot be attributed to task contingencies; when it can, ease of retrieval ceases to be informative.     

Testing the myth of the encoding–retrieval match

The view that successful memory performance depends importantly on the extent to which there is a match between the encoding and retrieval conditions is commonplace in memory research. However, Nairne (Memory, 10, 389–395, 2002) proposed that this idea about trace–cue compatibility being the driving force behind memory retention is a myth, because one cannot make unequivocal predictions about performance by appealing to the encoding–retrieval match. What matters instead is the relative diagnostic value of the match, and not the absolute match. Three experiments were carried out in which participants memorised word pairs and tried to recall target words when given retrieval cues. The diagnostic value of the cue was varied by manipulating the extent to which the cues subsumed other memorised words and the level of the encoding–retrieval match. The results supported Nairne’s (Memory, 10, 389–395, 2002) assertion that the diagnostic value of retrieval cues is a better predictor of memory performance than the absolute encoding–retrieval match.     

The mechanism of priming: episodic retrieval or priming of pop-out?

Previous studies indicate that priming affects attentional processes, facilitating processes of target detection and selection on repetition trials. However, the results are so far compatible with two different attentional views that propose entirely different mechanisms to account for priming. The priming of pop-out hypothesis explains priming by feature weighting processes that lead to more frequent selections of nontarget items on switch trials. According to the episodic retrieval account, switch trials conversely lead to temporal delays in retrieving priority rules that specify the target. The results from two eye tracking experiments clearly favour the priming of pop-out hypothesis: Switching the target and nontarget features leads to more frequent selection of nontargets, without affecting the time-course of saccades to a great extent. The results from two more control experiments demonstrate that the same results can be obtained in a visual search task that allows only covert attention shifts. This indicates that eye movements can reliably indicate covert attention shifts in visual search.     

Attentional control of the creation and retrieval of stimulus–response bindings

Two experiments studied the degree to which the creation and retrieval of episodic feature bindings is modulated by attentional control. Experiment 1 showed that the impact of bindings between stimulus and response features varies as a function of the current attentional set: only bindings involving stimulus features that match the current set affect behavior. Experiment 2 varied the time point at which new attentional sets were implemented—either before or after the processing of the to-be-integrated stimuli and responses. The time point did not matter, suggesting that the attentional set has no impact on feature integration proper but controls which features get access to and can thus trigger the retrieval of bindings.     

Is the benefit of retrieval practice modulated by motivation?

Retrieval practice tends to produce better long-term learning than rereading, but laboratory studies have typically used arbitrary material that subjects may not care to learn. The observed advantage of retrieval practice may be exaggerated because low motivation may result in deficient processing during (usually passive) rereading. Thus, when subjects are motivated to learn the material, the type of study strategy (whether retrieval practice or rereading) might be less important. To test this hypothesis, we conducted 3 experiments in which we manipulated the incentives (using monetary bonuses or time savings) for learning Swahili–English word pairs. Items that had undergone retrieval practice were better recalled than reread items on a final test 2 days later, but this effect did not interact with incentive level. These results provide some reassurance that lab findings from the testing effects literature likely generalize to real-world situations in which motivation to learn may be greater.     

Does scene context always facilitate retrieval of visual object representations?

An object-to-scene binding hypothesis maintains that visual object representations are stored as part of a larger scene representation or scene context, and that scene context facilitates retrieval of object representations (see, e.g., Hollingworth, Journal of Experimental Psychology: Learning, Memory and Cognition, 32, 58-69, 2006). Support for this hypothesis comes from data using an intentional memory task. In the present study, we examined whether scene context always facilitates retrieval of visual object representations. In two experiments, we investigated whether the scene context facilitates retrieval of object representations, using a new paradigm in which a memory task is appended to a repeated-flicker change detection task. Results indicated that in normal scene viewing, in which many simultaneous objects appear, scene context facilitation of the retrieval of object representations-henceforth termed object-to-scene binding-occurred only when the observer was required to retain much information for a task (i.e., an intentional memory task).     

Understanding priming of color-singleton search: Roles of attention at encoding and “retrieval”

We investigated how the performance of a color-singleton search (the search for a single odd-colored item among homogeneously colored distractors) left a persistent memory trace (lasting up to six intervening trials or ～17 sec) that facilitated a subsequent color-singleton search (when the same targetdistractor color combination was repeated). Specifically, we investigated the roles of attention in the encoding and “retrieval” stages of this priming effect by intermixing trials in which the target location was precued by an onset cue. We found that the encoding of both target and distractor colors was automatic in that whether or not observers had to use color in locating the target in the preceding trial did not substantially affect priming. However, priming required that the color-singleton item be attended in the preceding trial. Once a color singleton display was encoded, our results indicated that priming facilitated the direction of attention to the color-singleton target on a subsequent trial. In short, when a color-singleton item happened to be a critical item to be attended in one situation, another color-singleton item defined by the same color combination tended to attract attention in subsequent encounters.     

Amnesia or retrieval deficit? Implications of a molecular approach to the question of reconsolidation

Post-retrieval interference with a memory has uncovered a phenomenon known to the field as reconsolidation. In this article, we will review the specific molecular mechanisms that have been implicated in reconsolidation. As a result of numerous studies over the past five years, it can now be said with a fair amount of certainty that reconsolidation is not a recapitulation of the mechanisms underlying consolidation, despite what the term "reconsolidation" may suggest. Therefore, in addition to reviewing the known mechanisms of reconsolidation, we will propose that two experimental approaches involving the targeting of specific molecular mechanisms, and the study of these mechanisms during retrieval, may serve useful to the field as it is now able to advance beyond comparisons between consolidation and reconsolidation.     

Can inhibition resolve retrieval competition through the control of spreading activation?

Two experiments are reported in which the mechanisms underlying retrieval-induced forgetting for complex prose materials were investigated, using the independent probe technique pioneered by Anderson and Spellman (1995). These experiments provide additional empirical evidence in support of an inhibitory account of memory. Specifically, evidence emerged not only for the inhibition of nonpracticed items from practiced sets (i.e., first-order effects), but also for the inhibition of items from nonpracticed sets that were semantically related to practiced items in practiced sets (i.e., cross-category effects) and for items from nonpracticed sets that were semantically related to nonpracticed items in practiced sets (ie., second-order effects). These findings are considered in terms of Anderson and Spellman's model of inhibitory processing. We also outline an alternative inhibitory interpretation. Specifically, we consider how inhibition may function as a way of controlling the spread of activation and what implications this may have for the flexibility and adaptiveness of memory.     

When do response-related episodic retrieval effects co-occur with inhibition of return?

Attention, Perception, & Psychophysics - At some point, spatial priming effects more faithfully reflect response selection processes than they do attentional orienting or sensory processes....     

Is saccade-induced retrieval enhancement a potential means of improving eyewitness evidence?

Saccade-induced retrieval enhancement (SIRE) is the effect whereby making bilateral saccades enhances the subsequent retrieval of memories. Two experiments explored SIRE's potential to improve eyewitness evidence. Participants viewed slideshows depicting crimes, and received contradictory and additive misinformation about event details either once (Experiment 1) or three times (Experiment 2). Participants then performed saccades or a fixation control task before being tested on their memory for the slideshows and making confidence judgements. Saccades increased discrimination between seen and unseen event details regardless of whether or what type of misinformation was presented. Because prior studies indicated that SIRE might be more robust for individuals who are strongly right-handed versus not, we examined SIRE as a function of handedness and found that saccades improved memory for event details regardless of participants' handedness. However, participants who were not strongly right-handed had fewer false memories than participants who were strongly right-handed, extending previous findings of superior memory among individuals who are not strongly right-handed. Saccades also increased confidence in true memories (Experiment 1) and decreased confidence in false memories (Experiment 2). The results support SIRE's potential to improve eyewitness evidence.     

Adults’ strategy choices for simple addition: Effects of retrieval interference

Simple addition (e.g., 3 + 2, 7 + 9) may be performed by direct memory retrieval or by such procedures as counting or transformation. The distribution of associations (DOA) model of strategy choice (Siegler, 1988) predicts that procedure use should increase as retrieval interference increases. To test this, 100 undergraduates performed simple addition problems, either after blocks of simple multiplication (high-interference context) or after blocks of simple division problems (low-interference context). Addition took longer and was more error prone after multiplication; in particular, there were more multiplication confusion errors on the relatively easy, small-number addition problems (e.g., 3 + 2 = 6, 4 + 3 = 12), but not on the more difficult, large-number additions. Consistent with the DOA, participants reported greater use of procedures for addition after multiplication, but more so for small addition problems. The findings demonstrate that adults’ use of procedural strategies for simple addition is substantially influenced by retrieval interference.     

Do dichotic listening procedures measure lateralization of information processing or retrieval strategy?

The data from two dichotic studies, both of which evaluated spontaneously generated response strategies under free recall and one of which also manipulated retrieval strategy by instruction, supported a conception that what dichotic procedures mostly measure are response strategies—mobile and readily deployed without loss of mnemonic capability. Consequently, competitional methods which are heavily influenced by output factors appear to be unreliable as a means of evaluating input processing dominance.     

Why are names of people associated with so many phonological retrieval failures?

Two experiments are reported that revisit the issue of why people’s names are more difficult to recall than common names such as the names of objects. In Experiment 1, retrieval of the names of a set of object pictures was compared with recall of a set of names of famous faces. The object and face sets were matched for preexperimental familiarity. The results showed significantly more tip-of-the tongue (TOT) states and significantly poorer name recall for faces than for objects. Although the overall numbers of incorrect answers for the two sets of items did not differ, the incorrect answers in the face condition were mostly “don’t know” responses, whereas incorrect answers for objects were mostly alternative names. In Experiment 2, written definitions were used instead of pictures, and target items were selected so as to keep the number of alternatives to a minimum. Under these circumstances, there were no differences in either the number of items correctly named or the number of TOTs for common and people’s names. These findings are consistent with the views of Brédart (Memory, 1, 351–366, 1993), who argued that there are fewer documented TOTs for common names because a semantically related alternative often comes to mind when a participant is experiencing, or is about to experience, a retrieval failure.     

Do alternative names block young and older adults' retrieval of proper names?

This study evaluates whether tip of the tongue experiences (TOTs) are caused by a more accessible word which blocks retrieval of the target word, especially for older adults. In a "competitor priming" paradigm, young and older adults produced the name of a famous character (e.g., Eliza Doolittle) in response to a question and subsequently named a picture of a famous actor or actress depicting this character (e.g., Audrey Hepburn as Eliza Doolittle). Older adults produced more TOTs than young adults, but prior production of a related character name did not affect TOTs, although it did reduce incorrect responses. There were no age differences in knowledge of films and TV and thus the age-related increase in TOTs is not because older adults have more relevant knowledge. The findings are compatible with models in which alternate words are a consequence not a cause of TOT.     

Can people strategically control the encoding and retrieval of some morphologic and typographic details of words?

This study investigated whether the encoding and retrieval of plurality information and letter-case information of words in recognition memory can be inhibited. Response-deadline experiments (Hintzman & Curran, 1994) using single words have indicted a controlled processing mode, whereas studies using meaningful sentences (e.g., Jou & Harris, 1991) have indicated an automatic mode of processing plurality information. Two similar opposing views have existed on the processing of letter-case information. The abstractionist view contends that we retain the abstract lexical information and discard the superficial perceptual case information. The proceduralist view holds that perceptual details cannot be separated from the lexical information. Using an intentional and an attention-diverted learning procedure and instructions to ignore plurality and case, we found that subjects experienced a consistent interference effect of changed plurality from study to test but slightly less interference from changed case, suggesting strong automaticity for plurality, and comparatively less automaticity, for case processing.     

When's your birthday? The self‐reference effect in retrieval of dates

Material encoded with reference to the self is better remembered. One interpretation of this effect is that the self operates to organise retrieval of memories. We were motivated to find out whether this organisational principle extended to everyday information and for material not explicitly related to the self. Participants generated friends' birthdays from memory and then gave their own birthday. We found that participants were particularly likely to recall birthdays from on or around the date of their own birthday. Thus, memory for birthdays clusters around self‐relevant information, even when there is no specific attempt to recall self‐related material. Birthdays clustered somewhat around the time of testing, important dates in the calendar, and for a close other, but not to the extent of the participants' birthdays. We suggest this is a demonstration of the organisational structure of the self in memory. Copyright © 2010 John Wiley & Sons, Ltd.     

Can imagery be distinguished from other forms of internal representation? Evidence from studies of information retrieval times

This paper provides support for the notion that images, once formed, are a distinct form of internal representation, processed differently than other forms of internal representation. In two experiments, subjects decided as quickly as possible whether or not named animals had given properties. When imagery was not used, people verified properties more quickly in accordance with how strongly associated the property was with the animal in question. When images of the whole animal were consulted, in contrast, subjects were faster in accordance with increasing size of the property, and not with increasing association strength. However, if subjects imaged only the local region where a property ought to be found, and did not consult an image of the whole animal, the size of a property no longer influenced verification time. These results and their implications for the debate over imagery vs. propositional representation were discussed.