Serial Position Effects Research Articles

Item-properties may influence item-item associations in serial recall.

Attributes of words, such as frequency and imageability, can influence memory for order. In serial recall, Hulme, Stuart, Brown, and Morin (Journal of Memory and Language, 49(4), 500-518, 2003) found that high-frequency words were recalled worse, and low-frequency words better, when embedded in alternating lists than pure lists. This is predicted by associative chaining, wherein each recalled list-item becomes a recall-cue for the next item. However, Hulme, Stuart, Brown, and Morin (Journal of Memory and Language, 49(4), 500-518, 2003) argued their findings supported positional-coding models, wherein items are linked to a representation of position, with no direct associations between items. They suggested their serial-position effects were due to pre-experimental semantic similarity between pairs of items, which depended on frequency, or a complex tradeoff between item- and order-coding (Morin, Poirier, Fortin, & Hulme, Psychonomic Bulletin Review, 13(4), 724-729, 2006). We replicated the smooth serial-position effects, but accounts based on pre-existing similarity or item-order tradeoffs were untenable. Alternative accounts based, on imageability, phonological and lexical neighbourhood sizes were also ruled out. The standard chaining account predicts that if accuracy is conditionalized on whether the prior item was correct, the word-frequency effect should reappear in alternating lists; however, this prediction was not borne out, challenging this retrieval-based chaining account. We describe a new account, whereby frequency influences the strengths of item-item associations, symmetrically, during study. A manipulation of word-imageability also produced a pattern consistent with item-item cueing at study, but left room for effects of imageability at the final stage of recall. These findings provide further support for the contribution of associative chaining to serial-recall behaviour and show that item-properties may influence serial-recall in multiple ways.

Short-term memory development: Differences in serial position curves between age groups and latent classes

In studies on the development of cognitive processes, children are often grouped based on their ages before analyzing the data. After the analysis, the differences between age groups are interpreted as developmental differences. We argue that this approach is problematic because the variance in cognitive performance within an age group is considered to be measurement error. However, if a part of this variance is systematic, it can provide very useful information about the cognitive processes used by some children of a certain age but not others. In the current study, we presented 210 children aged 5 to 12years with serial order short-term memory tasks. First we analyze our data according to the approach using age groups, and then we apply latent class analysis to form latent classes of children based on their performance instead of their ages. We display the results of the age groups and the latent classes in terms of serial position curves, and we discuss the differences in results. Our findings show that there are considerable differences in performance between the age groups and the latent classes. We interpret our findings as indicating that the latent class analysis yielded a much more meaningful way of grouping children in terms of cognitive processes than the a priori grouping of children based on their ages.

Absolute and relative temporal order memory for performed activities following stroke

Reconstructing the temporal order of events is a crucial part of episodic memory. The temporal dimension, however, is often discarded in clinical settings, and measurements of true temporal aspects of episodic memory are scarce. The present study assessed temporal memory in stroke patients and in age- and education-matched healthy controls. Both groups underwent a standardized neuropsychological examination. We asked participants afterwards to reconstruct the order of tests they had performed, measured in absolute temporal order (event placed on correct moment in sequence) and relative temporal order (event placed correctly relative to directly preceding and following events). The aim of the study was to examine how serial-position curve effects (measuring absolute temporal order anchored in exact time) and how relative temporal order memory (anchored to other events) may differ in a group of cerebral stroke patients. Another aim was to link temporal order memory deficits with established neuropsychological measures of cognitive functioning. Although item identification was comparable in both groups, absolute temporal order memory was impaired in patients: A total of 43% of the patients lacked the expected primacy and recency effects (serial position effect). In addition, relative temporal order memory was affected in this group as well, F(1, 70) = 4.08, p < .05; 25% of the patients were impaired in reconstructing the relative temporal order (p = .019, Fisher’s Exact Test). Both absolute and relative temporal order memory performance related to the domains of executive functioning and memory. Our results suggest that it is important to test both absolute and relative temporal order memory, especially because these types of memory depend on different anchors, either on time or on adjacent events.

Serial-Position Effects in Evaluative Judgments

Serial evaluations are the basis of many judgment and decision processes (e.g., in sports, talent shows, or academic examinations). We address the advantages and disadvantages of being in the beginning or the end of such evaluation series. We propose that for serial evaluations, people must calibrate a transformation function that translates observable stimulus input (e.g., performances) into available judgment categories (e.g., “pass” or “fail”). Until this function is calibrated, people are motivated to avoid extreme categories. Therefore, being good in the beginning is disadvantageous because one is more likely to be categorized as “average” than “good,” whereas being bad is advantageous because one is more likely to be categorized “average” than “bad.” We present real-life and laboratory examples of the proposed calibration effects and compare the calibration explanation with other accounts of serial-position effects. Based on these theoretical considerations, we suggest possible ways to avoid these position effects in serial evaluations.

Within-word serial order control: Adjacent mora exchange and serial position effects in repeated single-word production

An essential function of language processing is serial order control. Computational models of serial ordering and empirical data suggest that plan representations for ordered output of sound are governed by principles related to similarity. Among these principles, the temporal distance and edge principles at a within-word level have not been empirically demonstrated separately from other principles. Specifically, the temporal distance principle assumes that phonemes that are in the same word and thus temporally close are represented similarly. This principle would manifest as phoneme movement errors within the same word. However, such errors are rarely observed in English, likely reflecting stronger effects of syllabic constraints (i.e., phonemes in different positions within the syllable are distinctly represented). The edge principle assumes that the edges of a sequence are represented distinctly from other elements/positions. This principle has been repeatedly observed as a serial position effect in the context of phonological short-term memory. However, it has not been demonstrated in single-word production. This study provides direct evidence for the two abovementioned principles by using a speech-error induction technique to show the exchange of adjacent morae and serial position effects in Japanese four-mora words. Participants repeatedly produced a target word or nonword, immediately after hearing an aurally presented distractor word. The phonologically similar distractor words, which were created by exchanging adjacent morae in the target, induced adjacent-mora-exchange errors, demonstrating the within-word temporal distance principle. There was also a serial position effect in error rates, such that errors were mostly induced at the middle positions within a word. The results provide empirical evidence for the temporal distance and edge principles in within-word serial order control.

Poster #T58 LOWER ANTERIOR CINGULATE VOLUME IN SERIOUSLY VIOLENT MEN WITH ANTISOCIAL PERSONALITY DISORDER OR SCHIZOPHRENIA AND A HISTORY OF CHILDHOOD ABUSE

Three experiments examined whether or not benchmark findings observed in the immediate retrieval from episodic memory are similarly observed over much greater time-scales. Participants were presented with experimentally-controlled lists of words at the very slow rate of one word every hour using an iPhone recall application, RECAPP, which was also used to recall the words in either any order (free recall: Experiments 1 to 3) or the same order as presented (serial recall: Experiment 3). We found strong temporal contiguity effects, weak serial position effects with very limited recency, and clear list length effects in free recall; clear primacy effects and classic error gradients in serial recall; and recency effects in a final two-alternative forced choice recognition task (Experiments 2 and 3). Our findings extend the timescales over which temporal contiguity effects have been observed, but failed to find consistent evidence for strong long-term recency effects with experimenter-controlled stimuli.

When working memory updating requires updating: Analysis of serial position in a running memory task

This study aimed to investigate updating in working memory (WM), analyzing the effects of task demand and memory resources on serial position curve (SPC), in a running memory task with slow pace presentation and a probed recognition procedure. These task conditions were supposed to produce an easier WM updating task, which may allow evidencing whether the task is performed through an active or a passive updating.Serial position curves were compared in conditions of high or low memory load, and with or without interference of a secondary (prospective memory, PM) task. With either a high WM load, or a high PM load, results showed a SPC with both primacy and recency effects, indicating the use of an active strategy. When resources were taken up by both PM task and high WM demand the usual pattern with only recency effect was obtained.Taken together, these findings support the ideas that 1 — people can effectively update WM, and 2 — the performance is dependent on both memory and executive resource availability.

What we talk about when we talk about access deficits.

Semantic impairments have been divided into storage deficits, in which the semantic representations themselves are damaged, and access deficits, in which the representations are intact but access to them is impaired. The behavioural phenomena that have been associated with access deficits include sensitivity to cueing, sensitivity to presentation rate, performance inconsistency, negative serial position effects, sensitivity to number and strength of competitors, semantic blocking effects, disordered selection between strong and weak competitors, correlation between semantic deficits and executive function deficits and reduced word frequency effects. Four general accounts have been proposed for different subsets of these phenomena: abnormal refractoriness, too much activation, impaired competitive selection and deficits of semantic control. A combination of abnormal refractoriness and impaired competitive selection can account for most of the behavioural phenomena, but there remain several open questions. In particular, it remains unclear whether access deficits represent a single syndrome, a syndrome with multiple subtypes or a variable collection of phenomena, whether the underlying deficit is domain-general or domain-specific, whether it is owing to disorders of inhibition, activation or selection, and the nature of the connection (if any) between access phenomena in aphasia and in neurologically intact controls. Computational models offer a promising approach to answering these questions.

Serial position effects are sensitive predictors of conversion from MCI to Alzheimer's disease dementia

BackgroundIt is unclear whether the predictive strength of established cognitive variables for progression to Alzheimer's disease (AD) dementia from mild cognitive impairment (MCI) varies depending on time to conversion. We investigated which cognitive variables were best predictors, and which of these variables remained predictive for patients with longer times to conversion. MethodsSeventy-five participants with MCI were assessed on measures of learning, memory, language, and executive function. Relative predictive strengths of these measures were analyzed using Cox regression models. ResultsMeasures of word-list position—namely, serial position scores—together with Short Delay Free Recall of word-list learning best predicted conversion to AD dementia. However, only serial position scores predicted those participants with longer time to conversion. ConclusionsResults emphasize that the predictive strength of cognitive variables varies depending on time to conversion to dementia. Moreover, finer measures of learning captured by serial position scores were the most sensitive predictors of AD dementia.

Is memory search governed by universal principles or idiosyncratic strategies?

Laboratory paradigms have provided an empirical foundation for much of psychological science. Some have argued, however, that such paradigms are highly susceptible to idiosyncratic strategies and that many findings do not reflect fundamental cognitive principles but are instead artifacts of averaging across participants who employ different strategies. We developed a set of techniques to rigorously test the extent to which average data are distorted by such strategy differences and applied these techniques to free recall data from the Penn Electrophysiology of Encoding and Retrieval Study. Recall initiation showed evidence of subgroups: The majority of participants initiated recall from the last item in the list, but one subgroup showed elevated initiation probabilities for items 2 to 4 positions back from the end of the list, and another showed elevated probabilities for the beginning of the list. By contrast, serial position curves and temporal and semantic clustering functions were remarkably consistent, with almost every participant exhibiting a recognizable version of the average function, suggesting that these functions reflect fundamental principles of the memory system. The approach taken here can serve as a model for evaluating the extent to which other laboratory paradigms are influenced by individual differences in strategy use.

Role of Information on Consumers’ Willingness‐to‐pay for Genetically‐modified Rice with Health Benefits: An Application to China

Despite their potential health benefits, the controversial nature surrounding the use of GM technology in biofortified crops remains a subject of discussion. This paper investigates the role of information on willingness‐to‐pay for folate‐biofortified rice in a Chinese folate‐deficient region. We conducted second price auctions with 252 women of childbearing age, split up into two target groups based on street (n = 132, non‐student sample) or school auctions (n = 120, student sample). Notwithstanding a general positive effect of folate‐related information (i.e. content, benefits and regional situation), evidence reveals that the non‐student sample is less concerned about GM technology. The results also provide insight into serial position effects in conflicting GM information. Whereas participants in the non‐student sample are more prone to a primacy bias when receiving both positive and negative information, an alarmist reaction is observed in the student sample. This study highlights the need for segmented, targeted communication strategies on biofortification.

Odor-context effects in free recall after a short retention interval: A new methodology for controlling adaptation

The present study investigated context effects of incidental odors in free recall after a short retention interval (5 min). With a short retention interval, the results are not confounded by extraneous odors or encounters with the experimental odor and possible rehearsal during a long retention interval. A short study time condition (4 s per item), predicted not to be affected by adaptation to the odor, and a long study time condition (8 s per item) were used. Additionally, we introduced a new method for recovery from adaptation, where a dissimilar odor was briefly presented at the beginning of the retention interval, and we demonstrated the effectiveness of this technique. An incidental learning paradigm was used to prevent overshadowing from confounding the results. In three experiments, undergraduates (N = 200) incidentally studied words presented one-by-one and received a free recall test. Two pairs of odors and a third odor having different semantic-differential characteristics were selected from 14 familiar odors. One of the odors was presented during encoding, and during the test, the same odor (same-context condition) or the other odor within the pair (different-context condition) was presented. Without using a recovery-from-adaptation method, a significant odor-context effect appeared in the 4-s/item condition, but not in the 8-s/item condition. Using the recovery-from-adaptation method, context effects were found for both the 8- and the 4-s/item conditions. The size of the recovered odor-context effect did not change with study time. There were no serial position effects. Implications of the present findings are discussed.

Articulatory Rehearsal Is More Than Refreshing Memory Traces

This study examined whether additional articulatory rehearsal induced temporary durability of phonological representations, using a 10-s delayed nonword free recall task. Three experiments demonstrated that cumulative rehearsal between the offset of the last study item and the start of the filled delay (Experiments 1 and 3) and a fixed rehearsal of the immediate item during the subsequent interstimulus interval (Experiments 2 and 3) improved free recall performance. These results suggest that an additional rehearsal helps to stabilize phonological representations for a short period. Furthermore, the analyses of serial position curves suggested that the frequency of the articulation affected the durability of the phonological representation. The significance of these findings as clues of the mechanism maintaining verbal information (i.e., verbal working memory) is discussed.

Serial Position Effects in Patients with Mild Cognitive Impairment and Early and Moderate Alzheimer's Disease Compared with Healthy Comparison Subjects

Background/Aims: This study aimed to investigate whether the serial position effects in memory can differentiate patients with different subtypes of mild cognitive impairment (MCI) from healthy controls and patients with different stages of Alzheimer's disease (AD). Methods: The serial position effects was tested with the CERAD word list task in 184 persons (39 healthy control subjects, 15 amnestic MCI single domain subjects, 23 amnestic MCI multiple domain subjects, 31 nonamnestic MCI subjects, 45 early or mild AD patients, and 31 moderate AD patients). Results: With progression of dementia, memory deficits increased and the impairment in the primacy effect during the learning trials advanced, whereas the recall of recent items was less impaired. The serial position profile of nonamnestic MCI patients resembled that of healthy control subjects, whereas amnestic MCI patients showed poorer performance in all 3 positions but no significant difference as a function of serial word position. Conclusion: Analyses of the serial position effect may be a useful complement to clinical neuropsychological measures for distinguishing amnestic MCI patients from normal aging and patients with different stages of dementia.

Serial position effect in tactile roughness recognition

Serial position effect in tactile roughness recognition

Dichotic Assessment of Verbal Memory Function: Development and Validation of the Persian Version of Dichotic Verbal Memory Test

The Dichotic Verbal Memory Test (DVMT) is useful in detecting verbal memory deficits and differences in memory function between the brain hemispheres. The purpose of this study was to prepare the Persian version of DVMT, to obtain its results in 18- to 25-yr-old Iranian individuals, and to examine the ear, gender, and serial position effect. The Persian version of DVMT consisted of 18 10-word lists. After preparing the 18 lists, content validity was assessed by a panel of eight experts and the equivalency of the lists was evaluated. Then the words were recorded on CD in a dichotic mode such that 10 words were presented to one ear, with the same words reversed simultaneously presented to the other ear. Thereafter, it was performed on a sample of young, normal, Iranian individuals. Thirty normal individuals (no history of neurological, ontological, or psychological diseases) with ages ranging from 18 to 25 yr were examined for evaluating the equivalency of the lists, and 110 subjects within the same age range participated in the final stage of the study to obtain the normative data on the developed test. There was no significant difference between the mean scores of the 18 developed lists (p > 0.05). The mean content validity index (CVI) score was .96. A significant difference was found between the mean score of the two ears (p < 0.05) and between female and male participants (p < 0.05). The Persian version of DVMT has good content validity and can be used for verbal memory assessment in Iranian young adults.

Evaluating Physician-to-Patient Communication

Research has established that human patient simulators (i.e., standardized patients) are a highly beneficial component of modern medical education and training, but few studies have explored the cognitive factors that affect the ability of standardized patients to make clinical skills assessments during simulated patient encounters. This study examines the impact of multiple scenario evaluation points (as opposed to a single, postscenario evaluation) and serial position effects on the accuracy of verbal and nonverbal clinical performance evaluations. Results suggest that concurrent recall may result in better verbal and nonverbal recall accuracy for clinical skills assessment than the traditional retrospective framework. For formative clinical skills assessment, in which specificity for the purpose of professional development is critical, concurrent evaluation could be considered as a potential alternative to retrospective approaches.

Reactivation in working memory: an attractor network model of free recall.

The dynamic nature of human working memory, the general-purpose system for processing continuous input, while keeping no longer externally available information active in the background, is well captured in immediate free recall of supraspan word-lists. Free recall tasks produce several benchmark memory phenomena, like the U-shaped serial position curve, reflecting enhanced memory for early and late list items. To account for empirical data, including primacy and recency as well as contiguity effects, we propose here a neurobiologically based neural network model that unifies short- and long-term forms of memory and challenges both the standard view of working memory as persistent activity and dual-store accounts of free recall. Rapidly expressed and volatile synaptic plasticity, modulated intrinsic excitability, and spike-frequency adaptation are suggested as key cellular mechanisms underlying working memory encoding, reactivation and recall. Recent findings on the synaptic and molecular mechanisms behind early LTP and on spiking activity during delayed-match-to-sample tasks support this view.

P 35. Investigating a causal role of the supramarginal gyrus for pitch memory using transcranial direct current stimulation

Functional neuroimaging studies have shown an activation of the supramarginal gyrus during recognition pitch memory tasks and also showing a positive correlation of stronger activation of the left supramarginal gyrus and better task performance on the pitch memory task (Gaab et al., 2003, 2006). A previous transcranial direct current stimulation study using cathodal stimulation over the left supramarginal gyrus reported a detrimental effect on short-term pitch memory performance; indicating an important role of the left supramarginal gyrus for pitch memory (Vines et al., 2006). The current study investigated a causal involvement of the left supramarginal gyrus for the pitch memory process in non-musicians by using anodal and sham transcranial direct current stimulation to see whether this has a significant effect on the performance across different pitch memory paradigms (a recognition and a recall pitch memory task were used). A face memory task, used as a visual control task, was included to determine whether effects are specific to pitch memory. A between subject design was used. The two groups, which were matched by age, gender and pitch memory performance (evaluated in a preliminary test), either received anodal or sham stimulation over the left supramarginal gyrus and completed the three tasks in randomised order (between-subject design). The results show that the anodal group performed significantly better on both pitch memory tasks (see Figs. 1 and 2) but performance did not differ on the face memory task. These findings provide strong support for the causal involvement of the supramarginal gyrus specifically for the pitch memory process. Anodal stimulation facilitates pitch memory. Additionally, a post hoc analysis of the serial position curve of pitch items in the recall task showed that anodal transcranial direct current stimulation does not effect a particular point of the working-memory process (recency or primacy effects) but boosts pitch memory performance in general. Anodal stimulation over the supramarginal gyrus increased pitch memory performance significantly suggesting that the supramarginal gyrus could be responsible for the storage of pitch information in the memory process.

Effect of successive stimuli on sweetness intensity of gels and custards

Variations of tastant concentration during the consumption of food products were shown to enhance taste intensity. The aim of this study was to investigate the relation between the frequency at which tastant concentration is varied during the consumption of products and the occurrence of taste enhancement. For this purpose, the sweetness intensity of sequences of 4 successive sweet stimuli represented by cubes of a semi-solid gel or spoons of a model custard dessert was assessed. The intensity and the order of the stimuli within the sequences were varied to obtain 4 types of sucrose concentration profile (decreasing, increasing, middle peak and boundary peak) at 2 magnitudes of concentration differences (small and large). Sequences of 4 stimuli containing a constant sucrose concentration were used as a reference. The sweetness intensity of the sequences of successive stimuli was assessed using line scale and time-intensity ratings.Line scale ratings showed that the type of sequence had an effect on sweetness intensity. A sweetness enhancement relative to the reference was observed in sequences that ended with high-intensity stimuli, whereas sweetness suppression was observed in sequences that ended with low-intensity stimuli. The observed sweetness enhancement and suppression were attributed to serial position effects (i.e. recency effects).Time-intensity ratings indicated that each stimulus in the sequences was evaluated individually by the assessors. Sequential effects seem to have occurred during the continuous evaluation of successive stimuli, since preceding stimuli in the sequences affected the evaluation of posterior stimuli. Furthermore, the overall sweetness intensity of the different sequences was not enhanced in relation to the reference. The lack of taste enhancement in sequences exhibiting variations of sucrose concentration was attributed mainly to the long period at which sucrose concentration was varied during the evaluation of the sequences. It was confirmed that the frequency of variation of tastant concentration affects the occurrence of taste enhancement.