Does survival processing enhance implicit memory?

Recent research has shown that human memory may have evolved to remember information that has been processed for the purpose of survival, more so than information that has been processed for other purposes, such as home-moving. We investigated this survival-processing advantage using both explicit and implicit memory tests. In Experiment 1, participants rated words in one of three scenarios: survival, pleasantness, and moving, followed by a timed stem-cued recall/stem-cued completion task. Items were completed more quickly in the survival scenario, as compared with the other two for the explicit task, but no differences were found across conditions in the implicit task. In Experiment 2, the implicit task was changed to concreteness judgments to encourage more conceptual processing. Again, the survival-processing advantage occurred in the explicit task (speeded item recognition), but not in the implicit task. These results suggest that a survival-processing advantage may benefit participants’ memory performance only during explicit retrieval.     

Does stress enhance or impair memory consolidation?

Three experiments examined the hypothesis that stress-induced arousal enhances long-term memory for experiences associated with arousing events. Contrary to expectations, in each experiment exposure to a stressor (arm immersion in ice water) interfered with, rather than enhanced, long-term memory for associated material. Despite varying the stimuli (words, pictures), their emotional value (positive, negative, neutral), the time between learning and stress inductions (0 to 1 minute), and opportunities for post-learning rehearsal, each experiment produced a significant reversal of the hypothesised effect. That is, in each experiment, exposure to a stressor interfered with, rather than enhanced, long-term memory for associated material. We conclude that the relationship between stress and memory consolidation is more bounded than previously believed.     

Does an instruction to forget enhance memory for other presented items?

In an item-method directed forgetting paradigm, participants were required to attend to one of two colored words presented on opposite sides of a central fixation stimulus; they were instructed to Remember or Forget the attended item. On a subsequent recognition test, the Attended words showed a typical directed forgetting effect with better recognition of Remember words than Forget words. Our interest was in the fate of the Unattended words. When the study display disappeared before the memory instruction, there was no effect of that instruction on unattended words; when the study display remained visible during presentation of the memory instruction, there was a reverse directed forgetting effect with better recognition of unattended words from Forget trials than from Remember trials. Incidental encoding of task-irrelevant stimuli occurs following presentation of a Forget instruction - but only when those task-irrelevant stimuli are still visible in the external environment.     

When does generation enhance memory for location?

Generation is thought to enhance both item-specific and relational processing of generated targets as compared with read words (M. A. McDaniel & P. J. Waddill, 1990). Generation facilitates encoding of the cue-target relation and sometimes boosts encoding of relations across list items. Of interest is whether generation can also increase the encoding of target-location associations. Because the literature on this point is mixed, 3 procedural differences between 2 studies (E. J. Marsh, G. Edelman, & G. H. Bower, 2001; N. W. Mulligan, 2004) were identified and manipulated. A positive generation effect was found for location memory, but this effect was reduced when subjects wrote down the study words and when the filler task involved generation. Generation can enhance location memory in addition to item memory but only if the experimental parameters do not interfere with the processing benefits of generation.     

Can survival processing enhance story memory? Testing the generalizability of the adaptive memory framework

Research from the adaptive memory framework shows that thinking about words in terms of their survival value in an incidental learning task enhances their free recall relative to other semantic encoding strategies and intentional learning (Nairne, Pandeirada, & Thompson, 2008). We found similar results. When participants used incidental survival encoding for a list of words (e.g., "Will this object enhance my survival if I were stranded in the grasslands of a foreign land?"), they produced better free recall on a surprise test than did participants who intentionally tried to remember those words (Experiment 1). We also found this survival processing advantage when the words were presented within the context of a survival or neutral story (Experiment 2). However, this advantage did not extent to memory for a story's factual content, regardless of whether the participants were tested by cued recall (Experiment 3) or free recall (Experiments 4-5). Listening to a story for understanding under intentional or incidental learning conditions was just as good as survival processing for remembering story content. The functionalist approach to thinking about memory as an evolutionary adaptation designed to solve reproductive fitness problems provides a different theoretical framework for research, but it is not yet clear if survival processing has general applicability or is effective only for processing discrete stimuli in terms of fitness-relevant scenarios from our past.     

Does overgeneral autobiographical memory result from poor memory for task instructions?

Considerable previous research has shown that retrieval of overgeneral autobiographical memories (OGM) is elevated among individuals suffering from various emotional disorders and those with a history of trauma. Although previous theories suggest that OGM serves the function of regulating acute negative affect, it is also possible that OGM results from difficulties in keeping the instruction set for the Autobiographical Memory Test (AMT) in working memory, or what has been coined "secondary goal neglect" (Dalgleish, 2004). The present study tested whether OGM is associated with poor memory for the task's instruction set, and whether an instruction set reminder would improve memory specificity over repeated trials. Multilevel modelling data-analytic techniques demonstrated a significant relationship between poor recall of instruction set and probability of retrieving OGMs. Providing an instruction set reminder for the AMT relative to a control task's instruction set improved memory specificity immediately afterward.     

Does overgeneral autobiographical memory result from poor memory for task instructions?

Considerable previous research has shown that retrieval of overgeneral autobiographical memories (OGM) is elevated among individuals suffering from various emotional disorders and those with a history of trauma. Although previous theories suggest that OGM serves the function of regulating acute negative affect, it is also possible that OGM results from difficulties in keeping the instruction set for the Autobiographical Memory Test (AMT) in working memory, or what has been coined “secondary goal neglect” (Dalgleish, 2004). The present study tested whether OGM is associated with poor memory for the task's instruction set, and whether an instruction set reminder would improve memory specificity over repeated trials. Multilevel modelling data-analytic techniques demonstrated a significant relationship between poor recall of instruction set and probability of retrieving OGMs. Providing an instruction set reminder for the AMT relative to a control task's instruction set improved memory specificity immediately afterward.     

What does it take for context to support action memory?

Previous research on the relation between context and action memory has given ambiguous results. Some experiments have found positive context effects, whereas other experiments have failed to demonstrate a context effect in action memory. Under nonmotor encoding conditions orderly action-locus pairings have been found to yield better recall than random pairings, this not being the case with motor encoding (Helstrup, 1989 a ). Three new experiments explored whether memory for loci could be linked with memory for action–using modified replications. The first experiment provided item-specific reasons for the action-locus connections, whereas the second experiment used a whole-list relational context task. Both experiments indicated that contexts can influence action memory also under enactment conditions, with strongest effect for whole-list contexts. The third experiment demonstrated how a positive context effect can be removed when the functional value of whole-list relational support cues is reduced.     

Children’s memory for counting-out rhymes: A cross-language comparison

In English, counting-out rhymes, such as “Eenie Meenie,” vary little over retellings. Recall is not rote but is sensitive to the structure of the genre. To test the generality of this finding, a sample of Romanian rhymes was collected. Although there was no overlap with the English rhymes, the corpus of rhymes collected had similar structure in terms of number of lines, repeating words, rhyme, alliteration, and the inclusion of nonsense words. Variation within rhymes preserved the poetic structure of the genre. The results suggest that verbatim recall can be schema driven if there is sufficient structure.     

Does echoic memory develop?

A series of experiments is reported on the stimulus suffix effect with the primary variables being age of the subject (7 and 11 years), rate of presentation, and list length. While the suffix effect was larger for younger subjects at a slow rate of presentation, the effect was nearly identical across age groups with a fast presentation rate. It was concluded that when the contaminating effects of more central processes are reduced, there is no developmental change in the capacity of echoic memory. An interesting effect of rate of presentation is reported with younger subjects performing better at faster rates of presentation and adults performing better at slower rates.     

Whose picture is this? Children's memory for item and source information

Children aged 3½ to 6½ years viewed pictures of common objects presented either once or three times on one of two consecutive days. A different hand puppet was used to present the pictures on each day, providing both perceptual and temporal cues to source. At test, old (studied) and new (non‐studied) pictures were presented for item recognition and source identification. Results showed that both item and source accuracy were higher for older (M = 5; 9 years) than younger children (M = 4; 6 years). Significant interactions between Age and Day of study were found for both item and source accuracy. For younger children, accuracy was higher for pictures studied on Day 1 than Day 2 (significant for source identification but not item recognition), whereas older children showed the opposite pattern: Higher accuracy for Day 2 than Day 1 (significant for item recognition but not source identification). Results are interpreted with respect to proactive interference and response bias. The utility of signal detection theory measures in determining the basis of age differences in performance of source identification is discussed.     

Does immediate imitation influence long-term memory for observed actions?

Long-term memory for object-related information acquired observationally was studied among younger and older toddlers under two conditions of acquisition and retention: direct imitation followed by reproduction after a 10 min delay (delayed imitation), and deferred imitation. A principal aim was to determine whether direct imitation fosters a form of enactive representation that improves long-term memory, or whether such memory is influenced more by visual encoding factors. Tasks consisted of five simple action combinations or separations. Results indicated that post-test scores were higher under all three post-test conditions than under pretest. Likewise, post-test performance was higher than that of a comparison group that did not observe the target actions. The results overall indicate that direct imitation did not operate substantially to improve memory for the modelled acts. Children were able to encode and retain about as much from their visual pickup of the modeled acts as from feedback obtained through the process of imitation. This finding was especially true for the older children.     

Can very small font size enhance memory?

Presenting information in a perceptually degraded format sometimes enhances learning outcomes. However, earlier studies in which words were presented in large or small fonts in a paradigm that also involved item-by-item judgments of learning (JOLs) consistently yielded no mnemonic benefit of small fonts. Can small font size enhance memory under hitherto unexamined conditions? A series of 11 experiments was conducted to examine systematically the effect of font size on memory for words and whether it depends on the strength of the font size manipulation, whether JOLs are solicited, the format of the test, and study time. The resulting data were meta-analyzed. Results yielded a u-shape relationship between font size and memory. Compared to intermediate fonts, there was a memory advantage for words presented in large fonts but also for words presented in very small fonts. However, the requirement to provide a JOL moderated the benefit of the very small font, which was eliminated when JOLs were solicited. Test format and study time did not moderate the effect of font size on memory. JOLs were insensitive to the u-shape relationship and consistently increased with font size. These findings provide support for the notion that perceptually degraded materials can enhance learning outcomes, but also highlight the importance of systematic investigation of moderators. The results shed new light on the inconsistent effects of manipulations of perceptual degradation on learning outcomes observed in earlier studies.     

Does frequency trajectory influence word identification? A cross-task comparison

In a series of six experiments, the influence of frequency trajectory in visual word recognition was investigated. In Experiment 1, frequency trajectory was found to exert a strong and reliable influence on age of acquisition (AoA) ratings. In word reading (Experiment 2), lexical decision (Experiments 3 and 6), proper name decision (Experiment 4), progressive demasking (Experiment 5), and a multiple regression analysis of lexical decision times taken from the French Lexicon Project, the effect of frequency trajectory was not reliable. In contrast, in all the experiments and in the multiple regression analysis, cumulative frequency had a strong and reliable influence on word recognition times. The findings firmly establish that in alphabetic languages such as French, age-limited learning effects do not surface readily in word recognition. In contrast, the total exposure to words across the lifetime is a strong determinant of word recognition speed. The implications of the findings are discussed.     

Is working memory necessary for implementation intentions to enhance prospective memory in older adults with cognitive problems?

Implementation intentions are an effective strategy for improving prospective memory in older adults. However, their efficacy has never been assessed in older individuals with cognitive problems (i.e., individuals with subjective memory complaints or objective memory impairments). Furthermore, although most authors consider implementation intentions to depend on automatic processes, some studies have shown the necessity of residual preserved controlled processes for implementation intentions to be efficient. We examined the efficacy of implementation intentions in prospective memory in 45 older participants consulting a memory clinic. Half of the participants were instructed to form an implementation intention, the other half receiving standard instructions. Analyses showed that working memory moderated the efficacy of implementation intentions, which were efficient only in individuals with better working memory. These results corroborate the claim that a minimal level of cognitive resources is required for the technique, although implementation intentions might depend principally on automatic processes.     

Does memory contaminate test-retest reliability?

The Wonderlic Personnel Test (1983) was administered twice over a 3-week period under conditions in which the activity of the second test was experimentally manipulated. Data from 302 undergraduates were analyzed. The standard test-retest reliability coefficient, .872, was not significantly different from the coefficients obtained from three other groups that, on the second test, were each given specific instructions: (a) to reason out the answers (pure reassess condition); (b) to use reasoning, memory of their initial responses, or both (reassess and memory); or (c) to take an alternate form of the test (parallel). However, the standard test-retest reliability coefficient was higher, p less than .10, than the coefficient obtained from a condition (pure memory) in which subjects were instructed to duplicate their previous responses, using only memory. Although the subjects in the test-retest and combined reassess and memory conditions reported recalling previous answers for 20-25% of the items on the second test, it was concluded that conscious repetition of specific responses did not seriously inflate the estimate of test-retest reliability.     

Multiple-target tracking: A role for working memory?

In order to identify the cognitive processes associated with target tracking, a dual-task experiment was carried out in which participants undertook a dynamic multiple-object tracking task first alone and then again, concurrently with one of several secondary tasks, in order to investigate the cognitive processes involved. The research suggests that after designated targets within the visual field have attracted preattentive indexes that point to their locations in space, conscious processes, vulnerable to secondary visual and spatial task interference, form deliberate strategies beneficial to the tracking task, before tracking commences. Target tracking itself is realized by central executive processes, which are sensitive to any other cognitive demands. The findings are discussed in the context of integrating dynamic spatial cognition within a working memory framework.     

Does source memory impairment associated with emotionally arousing stimuli occur at encoding or retrieval?

The present experiment investigated whether negatively arousing stimuli produce source memory impairment and whether the impairment occurs at encoding or retrieval. Participants were presented with negatively arousing, positively arousing, and neutral pictures. Each picture was followed by an instructional slide that indicated whether the picture was an Apple-kind or an Orange-kind. Item memory was assessed by free recall and source memory was assessed by asking participants to classify the recalled pictures into the two kinds of pictures. The results indicated that item memory was greater for the negatively arousing pictures than for the positively arousing and the neutral pictures. However, the negatively arousing pictures produced more misattribution errors than the neutral pictures, replicating source memory impairment. It was concluded that source memory impairment associated with negatively arousing stimuli occurs at encoding.     

Does motor encoding enhance relational information?

Summary Three experiments investigated whether learning action phrases by enacting the denoted action enhances organization or not. In the first experiment it was shown that, compared to a standard learning instruction, enacting did not enhance the clustering of episodic and taxonomic lists, but it did enhance memory performance. Furthermore, the enacting effect was strongest with an unrelated list; in all lists, organization and recall correlated only under a verbal instruction and not under an enacting instruction. In the second experiment, subjects were also informed about the categories of the lists and instructed to use them to learn the items. The organization was enhanced in all cases by this procedure, but the recall performance was enhanced only with a standard learning instruction. Under enacting, information about the categories had no influence. In the third experiment this effect was replicated for a taxonomic list and could be generalized for a motor list, in which categories were in accordance with the similarities of the movement pattern. Here too the explicit category information had an effect only under a standard learning instruction, but not with enacting. We interpret these effects as support for the assumption that enacting does not enhance memory performance by better relational information. Relational information is, on the contrary, less important for recall under enacting than under a standard learning instruction.