MEMORY: Serial Position Effects

From Wikipedia (quit smirking – this is a good overview of Serial Position Effect. Plus, I can reproduce it for you without violating copyright laws).

Serial-position effect is the tendency of a person to recall the first and last items in a series best, and the middle items worst.[1] The term was coined by Hermann Ebbinghaus through studies he performed on himself, and refers to the finding that recall accuracy varies as a function of an item’s position within a study list.[2] When asked to recall a list of items in any order (free recall), people tend to begin recall with the end of the list, recalling those items best (the recency effect). Among earlier list items, the first few items are recalled more frequently than the middle items (the primacy effect).[3][4]

One suggested reason for the primacy effect is that the initial items presented are most effectively stored in long-term memory because of the greater amount of processing devoted to them. (The first list item can be rehearsed by itself; the second must be rehearsed along with the first, the third along with the first and second, and so on.) The primacy effect is reduced when items are presented quickly and is enhanced when presented slowly (factors that reduce and enhance processing of each item and thus permanent storage). Longer presentation lists have been found to reduce the primacy effect.[4]

One theorized reason for the recency effect is that these items are still present in working memory when recall is solicited. Items that benefit from neither (the middle items) are recalled most poorly. An additional explanation for the recency effect is related to temporal context: if tested immediately after rehearsal, the current temporal context can serve as a retrieval cue, which would predict more recent items to have a higher likelihood of recall than items that were studied in a different temporal context (earlier in the list).[5] The recency effect is reduced when an interfering task is given. Intervening tasks involve working memory, as the distractor activity, if exceeding 15 to 30 seconds in duration, can cancel out the recency effect.[6] Additionally, if recall comes immediately after test, the recency effect is consistent regardless of the length of the studied list,[4] or presentation rate.[7]

Amnesiacs with poor ability to form permanent long-term memories do not show a primacy effect, but do show a recency effect if recall comes immediately after study.[8] People with Alzheimer’s disease exhibit a reduced primacy effect but do not produce a recency effect in recall.[9]

Primacy effect
The primacy effect, in psychology and sociology, is a cognitive bias that results in a subject recalling primary information presented better than information presented later on. For example, a subject who reads a sufficiently long list of words is more likely to remember words toward the beginning than words in the middle.

Many researchers tried to explain this phenomenon through free recall. Coluccia, Gamboz, and Brandimonte (2011) explain free recall as participants try to remember information without any prompting. In some experiments in the late 20th century it was noted that participants who knew that they were going to be tested on a list presented to them would rehearse items: as items were presented, the participants would repeat those items to themselves and as new items were presented, the participants would continue to rehearse previous items along with the newer items. It was demonstrated that the primacy effect had a greater influence on recall when there was more time between presentation of items so that participants would have a greater chance to rehearse previous (prime) items.[10][11][12]

Overt rehearsal was a technique that was meant to test participants’ rehearsal patterns. In an experiment using this technique, participants were asked to recite out loud the items that come to mind. In this way, the experimenter was able to see that participants would repeat earlier items more than items in the middle of the list, thus rehearsing them more frequently and having a better recall of the prime items than the middle items later on.[13]

In another experiment, by Brodie and Murdock, the recency effect was found to be partially responsible for the primacy effect.[14] In their experiment, they also used the overt-rehearsal technique and found that in addition to rehearsing earlier items more than later items, participants were rehearsing earlier items later on in the list. In this way, earlier items were closer to the test period by way of rehearsal and could be partially explained by the recency effect.

In 2013, a study showed that primacy effect is also prominent in decision making based on experience in a repeated-choice paradigm, a learning process also known as operant conditioning. The authors showed that importance attached to the value of the first reward on subsequent behaviour, a phenomenon they denoted as outcome primacy.[15]

In another study, participants received one of two sentences. For example, one may be given “Steve is smart, diligent, critical, impulsive, and jealous.” and the other “Steve is jealous, impulsive, critical, diligent, and smart.” These two sentences contain the same information. The first one suggests positive trait at the beginning while the second one has negative traits. Researchers found that the subjects evaluated Steve more positively when given the first sentence, compared with the second one.[16]

Recency effect
Two traditional classes of theories explain the recency effect.

Dual-store models
These models postulate that study items listed last are retrieved from a highly accessible short-term buffer, i.e. the short-term store (STS) in human memory. This allows items that are recently studied to have an advantage over those that were studied earlier, as earlier study items have to be retrieved with greater effort from one’s long-term memory store (LTS).

An important prediction of such models is that the presentation of a distraction, for example solving arithmetic problems for 10–30 seconds, during the retention period (the time between list presentation and test) attenuates the recency effect. Since the STS has limited capacity, the distraction displaces later study list items from the STS so that at test, these items can only be retrieved from the LTS, and have lost their earlier advantage of being more easily retrieved from the short-term buffer. As such, dual-store models successfully account for both the recency effect in immediate recall tasks, and the attenuation of such an effect in the delayed free recall task.

A major problem with this model, however, is that it cannot predict the long-term recency effect observed in delayed recall, when a distraction intervenes between each study item during the interstimulus interval (continuous distractor task).[17] Since the distraction is still present after the last study item, it should displace the study item from STS such that the recency effect is attenuated. The existence of this long-term recency effect thus raises the possibility that immediate and long-term recency effects share a common mechanism.[18]

Single-store models
According to single-store theories, a single mechanism is responsible for serial-position effects. A first type of model is based on relative temporal distinctiveness, in which the time lag between the study of each list item and the test determines the relative competitiveness of an item’s memory trace at retrieval.[17][19] In this model, end-of-list items are thought to be more distinct, and hence more easily retrieved.

Another type of model is based on contextual variability, which postulates that retrieval of items from memory is cued not only based on one’s mental representation of the study item itself, but also of the study context.[20][21] Since context varies and increasingly changes with time, on an immediate free-recall test, when memory items compete for retrieval, more recently studied items will have more similar encoding contexts to the test context, and are more likely to be recalled.

Outside immediate free recall, these models can also predict the presence or absence of the recency effect in delayed free recall and continual-distractor free-recall conditions. Under delayed recall conditions, the test context would have drifted away with increasing retention interval, leading to attenuated recency effect. Under continual distractor recall conditions, while increased interpresentation intervals reduce the similarities between study context and test context, the relative similarities among items remains unchanged. As long as the recall process is competitive, recent items will win out, so a recency effect is observed.

Ratio rule
Overall, an important empirical observation regarding the recency effect is that it is not the absolute duration of retention intervals (RI, the time between end of study and test period) or of inter-presentation intervals (IPI, the time between different study items) that matters. Rather, the amount of recency is determined by the ratio of RI to IPI (the ratio rule). As a result, as long as this ratio is fixed, recency will be observed regardless of the absolute values of intervals, so that recency can be observed at all time scales, a phenomenon known as time-scale invariance. This contradicts dual-store models, which assume that recency depends on the size of STS, and the rule governing the displacement of items in the STS.[citation needed]

Potential explanations either then explain the recency effect as occurring through a single, same mechanism, or re-explain it through a different type of model that postulates two different mechanisms for immediate and long-term recency effects. One such explanation is provided by Davelaar et al. (2005),[22] who argue that there are dissociations between immediate and long-term recency phenomena that cannot be explained by a single-component memory model, and who argues for the existence of a STS that explains immediate recency, and a second mechanism based on contextual drift that explains long-term recency.

Notes

  1. Coleman, Andrew (2006). Dictionary of Psychology (Second Edition). Oxford University Press. p. 688.
  2. Ebbinghaus, Hermann (1913). On memory: A contribution to experimental psychology. New York: Teachers College.
  3. Deese and Kaufman (1957) Serial effects in recall of unorganized and sequentially organized verbal material, J Exp Psychol. 1957 Sep;54(3):180-7
  4. Jump up to: a b c Murdock, Bennet (1962). “Serial Position Effect of Free Recall” (PDF). Journal of Experimental Psychology. 64 (5): 482–488. doi:10.1037/h0045106.
  5. Howard, Marc W.; Michael J. Kahana (2002). “A Distributed Representation of Temporal Context”. Journal of Mathematical Psychology. 46 (3): 269–299. doi:10.1006/jmps.2001.1388.
  6. Bjork, Robert A.; William B. Whitten (1974). “Recency-Sensitive Retrieval Processes in Long-Term Free Recall” (PDF). Cognitive Psychology. 6 (2): 173–189. doi:10.1016/0010-0285(74)90009-7. hdl:2027.42/22374.
  7. Murdock, Bennet; Janet Metcalf (1978). “Controlled Rehearsal in Single-Trial Free Recall”. Journal of Verbal Learning and Verbal Behavior. 17 (3): 309–324. doi:10.1016/s0022-5371(78)90201-3.
  8. Carlesimo, Giovanni; G.A. Marfia; A. Loasses; C. Caltagirone (1996). “Recency effect in anterograde amneisa: Evidence for distinct memory stores underlying enhanced retrieval of terminal items in immediate and delayed recall paradigms”. Neuropsychologia. 34 (3): 177–184. doi:10.1016/0028-3932(95)00100-x. PMID 8868275.
  9. Bayley, Peter J.; David P. Salmon; Mark W. Bondi; Barbara K. Bui; John Olichney; Dean C. Delis; Ronald G. Thomas; Leon J. Thai (March 2000). “Comparison of the serial-position effect in very mild Alzheimer’s disease, mild Alzheimer’s disease, and amnesia associated with electroconvulsive therapy”. Journal of the International Neuropsychological Society. 6 (3): 290–298. doi:10.1017/S1355617700633040.
  10. Glenberg, A.M; M.M. Bradley; J.A. Stevenson; T.A. Kraus; M.J. Tkachuk; A.L. Gretz (1980). “A two-process account of long-term serial position effects”. Journal of Experimental Psychology: Human Learning and Memory. 6 (4): 355–369. doi:10.1037/0278-7393.6.4.355.
  11. Marshall, P.H.; P.R. Werder (1972). “The effects of the elimination of rehearsal on primacy and recency”. Journal of Verbal Learning and Verbal Behavior. 11 (5): 649–653. doi:10.1016/s0022-5371(72)80049-5.
  12. Rundus, D (1980). “Maintenance rehearsal and long-term recency”. Memory and Cognition. 8 (3): 226–230. doi:10.3758/BF03197610.
  13. Rundus, D (1971). “An analysis of rehearsal processes in free recall”. Journal of Experimental Psychology. 89: 63–77. doi:10.1037/h0031185.
  14. Brodie, D.A.; B.B. Murdock (1977). “Effects of presentation time on nominal and functional serial-position curves in free recall”. Journal of Verbal Learning and Verbal Behavior. 16 (2): 185–200. doi:10.1016/s0022-5371(77)80046-7.
  15. Shteingart, Hanan; Tal Neiman; Yonatan Loewenstein (2013). “The Role of First Impression in Operant Learning” (PDF). Journal of Experimental Psychology: General. 142 (2): 476–488. doi:10.1037/a0029550. PMID 22924882.
  16. Asch, S (1946). “Forming impressions of personality”. Journal of Abnormal and Social Psychology. 41 (3): 258–290. CiteSeerX 10.1.1.463.2813. doi:10.1037/h0055756. PMID 20995551.
  17. Jump up to: a b Bjork & Whitten (1974). Recency sensitive retrieval processes in long-term free recall, Cognitive Psychology, 6, 173–189.
  18. Greene, R. L. (1986). “Sources of recency effects in free recall”. Psychological Bulletin. 99 (12): 221–228. doi:10.1037/0033-2909.99.2.221.
  19. Neath, I.; Knoedler, A. J. (1994). “Distinctiveness and serial position effects in recognition and sentence processing”. Journal of Memory and Language. 33 (6): 776–795. doi:10.1006/jmla.1994.1037.
  20. Howard, M. W.; Kahana, M. (1999). “Contextual variability and serial position effects in free recall”. Journal of Experimental Psychology: Learning, Memory, and Cognition. 24 (4): 923–941. CiteSeerX 10.1.1.360.18. doi:10.1037/0278-7393.25.4.923.
  21. Howard, M. W.; Kahana, M. J. (2002). “A distributed representation of temporal context”. Journal of Mathematical Psychology. 46 (3): 269–299. doi:10.1006/jmps.2001.1388.
  22. Davelaar, E. K.; Goshen-Gottstein, Y.; Ashkenazi, A.; Haarmann, H. J.; Usher, M. (2005). “The demise of short-term memory revisited: Empirical and computational investigations of recency effects”. Psychological Review. 112 (1): 3–42. doi:10.1037/0033-295x.112.1.3. PMID 15631586.

References

  • Coluccia, E.; Gamboz, N.; Brandimonte, M. A. (2011). “Normative data for a battery of free recall, cued recall and recognition tests in the elderly Italian population”. Neurol Sci. 32 (6): 1103–1114. doi:10.1007/s10072-011-0747-5. PMID 21918879.
  • Frensch, P.A. (1994). “Composition during serial learning: a serial position effect”. Journal of Experimental Psychology: Learning, Memory, and Cognition. 20 (2): 423–443. doi:10.1037/0278-7393.20.2.423.
  • Healy, A.F.; Havas, D.A.; Parkour, J.T. (2000). “Comparing serial position effects in semantic and episodic memory using reconstruction of order tasks”. Journal of Memory and Language. 42 (2): 147–167. doi:10.1006/jmla.1999.2671.
  • Howard, M. W.; Kahana, M. (1999). “Contextual Variability and Serial Position Effects in Free Recall”. Journal of Experimental Psychology: Learning, Memory, and Cognition. 25 (4): 923–941. CiteSeerX 10.1.1.360.18. doi:10.1037/0278-7393.25.4.923.
  • Kahana, M. J.; Howard, M. W.; Zaromb, F.; Wingfield, A. (2002). “Age dissociates recency and lag recency effects in free recall”. Journal of Experimental Psychology. 28 (3): 530–540. doi:10.1037/0278-7393.28.3.530.

Research Abstracts on Serial Position Effects

Effect of serial position on memorization.
Robinson, E. S. and Brown, M. A.
The American Journal of Psychology, 37, 1926. pp. 538-552.
Abstract:
Experiments with series of nonsense syllables and of numbers, in which the method of prompting was used, show that the advantages of both primacy and finality are pronounced; and primacy shows an even greater advantage than finality. The effect of primacy extends in some degree over several items in the first portion of a list, while the finality effect is more limited in scope. Curves of memorization have been constructed for the several items, which are like most other curves of learning in their general negative acceleration. The sharpness of deceleration varies according to the serial position of the item in question. The more favorably situated items show a sharper deceleration and there is evidence of early positive acceleration in the case of items which are unfavorably situated in very long lists.

The effect of serial position upon recall.
Jenkins, J. G. and Dallenbach, K. M.
The American Journal of Psychology, 38, 1927. pp. 285-291.
Abstract:
The data obtained in the writers’ earlier study of forgetting shows disagreement between the two observers in the relative recall of the first and last syllables in each series. There is, however, a definite correlation between the position of a syllable and the order in which it is recalled. It would seem that the effect of primacy, where evident, is due to an ‘initial set’ towards the first syllable, i.e., a tendency to report the first syllable first.

The influence of primacy.
Thorndike, E. L.
Journal of Experimental Psychology, Vol 10(1), Feb, 1927. pp. 18-29.
Abstract:
A test of the doctine of primacy (‘other things being equal the association first formed will prevail’). Subjects estimated the lengths of strips of paper and the areas of surfaces, drew lines of certain required lengths, represented certain sounds by letters, and added letters to make words of such combinations as ca, de, etc., and the similarity of the successive responses or estimations to the first response or estimation in the series was noted. The experiments lend no support to the doctrine that the first connection made with a situation is more important than any other in determining future connections. ‘In general, the first connection shows no greater potency over the n connections immediately following it than the second connection does over the n connections immediately following it. In general also the first connection shows no greater potency over those following it than the nth experience shows over those preceding it. On the contrary, in four of the six experiments there is much greater resemblance to what comes after than to what comes before.’ The facts which led to the formulation of the primacy principle are explained better by two corollaries of the general law of use or frequency.

Receiver operating characteristic analysis of eyewitness memory: Comparing the diagnostic accuracy of simultaneous versus sequential lineups.
Mickes, Laura, et.al.
Journal of Experimental Psychology: Applied, Vol 18(4), Dec, 2012. pp. 361-376.
Abstract:
A police lineup presents a real-world signal-detection problem because there are two possible states of the world (the suspect is either innocent or guilty), some degree of information about the true state of the world is available (the eyewitness has some degree of memory for the perpetrator), and a decision is made (identifying the suspect or not). A similar state of affairs applies to diagnostic tests in medicine because, in a patient, the disease is either present or absent, a diagnostic test yields some degree of information about the true state of affairs, and a decision is made about the presence or absence of the disease. In medicine, receiver operating characteristic (ROC) analysis is the standard method for assessing diagnostic accuracy. By contrast, in the eyewitness memory literature, this powerful technique has never been used. Instead, researchers have attempted to assess the diagnostic performance of different lineup procedures using methods that cannot identify the better procedure (e.g., by computing a diagnosticity ratio). Here, we describe the basics of ROC analysis, explaining why it is needed and showing how to use it to measure the performance of different lineup procedures. To illustrate the unique advantages of this technique, we also report 3 ROC experiments that were designed to investigate the diagnostic accuracy of simultaneous versus sequential lineups. According to our findings, the sequential procedure appears to be inferior to the simultaneous procedure in discriminating between the presence versus absence of a guilty suspect in a lineup.

Offloading memory: Serial position effects.
Kelly, Megan O. and Risko, Evan F.
Psychonomic Bulletin & Review, Vol 26(4), Aug, 2019. pp. 1347-1353.
Abstract:
Despite the long history and pervasiveness of cognitive offloading as a memory strategy, the memorial fate of offloaded information is not well understood. Recent work has suggested that offloading information may engage similar mechanisms as instructions to forget (e.g., directed forgetting). In the present investigation, we test this prediction by examining the serial position effect for offloaded information. Previous research has demonstrated that ‘forget’ instructions can eliminate the primacy effect while leaving an intact recency effect. Across two experiments, participants completed a number of free recall trials using an external aid and then a final recall trial without the external aid. We compared a group that was expecting to use the aid for the final trial (offloading) with a group that was not (no-offloading). We found a memory impairment for offloaded items that was characterized by a reduced primacy effect but a typical recency effect, similar to what has been reported in research on intentional/directed forgetting.

Distinct role of flexible and stable encodings in sequential working memory.Open Access
Lee, Hyeonsu, et.al.
Neural Networks, Vol 121, Jan, 2020. pp. 419-429.
Abstract:
The serial-position effect in working memory is considered important for studying how a sequence of sensory information can be retained and manipulated simultaneously in neural memory circuits. Here, via a precise analysis of the primacy and recency effects in human psychophysical experiments, we propose that stable and flexible codings take distinct roles of retaining and updating information in working memory, and that their combination induces serial-position effects spontaneously. We found that stable encoding retains memory to induce the primacy effect, while flexible encoding used for learning new inputs induces the recency effect. A model simulation based on human data, confirmed that a neural network with both flexible and stable synapses could reproduce the major characteristics of serial-position effects. Our new prediction, that the control of resource allocation by flexible–stable coding balance can modulate memory performance in sequence-specific manner, was supported by pre-cued memory performance data in humans.

Encoding dynamics in free recall: Examining attention allocation with pupillometry.
Unsworth, Nash, et.al.
Mem Cogn (2020). https://doi.org/10.3758/s13421-020-01077-7
Abstract:
In four experiments pupillary responses were used to examine attention allocation and encoding dynamics in free recall. In Experiment 1, pupillary responses increased (and then decreased) across serial position suggesting that attention was increasingly allocated to items during learning until working memory was overloaded. In Experiment 2, manipulating presentation duration resulted in larger and more sustained pupillary responses with increased presentation duration, suggesting that participants were likely engaging in more elaborative and attention-demanding processes. In Experiment 3a, manipulating list-length resulted in decreased pupillary responses across serial position suggesting that participants were prioritizing early list items and less attention was allocated to later items. In Experiment 3b, when list-length was known, pupillary responses in the long-list length condition tended to decrease across serial position whereas pupillary responses in the short list-length condition tended to increase and decrease across serial positon. These results suggest that participants flexibly allocate attention to items during encoding depending on the nature of the task and the types of processes that are engaged in. These results further suggest the potential of utilizing pupillary responses to track attention allocation during learning.

Serial position effects in the logical memory test: Loss of primacy predicts amyloid positivity.
Bruno, Davide, et.al
Journal of Neuropsychology, Dec 4, 2020.
Abstract:
Background Story recall is a frequently used neuropsychological test of episodic memory with clinical populations and for screening participants in drug trials for Alzheimer’s disease. However, it is unclear at this stage which underlying mechanisms confer the test its sensitivity. In this paper, we examined serial position effects, that is, better recall for items learned early and late on a list, in story recall, and their usefulness to predict early changes associated with neurodegenerative markers. Methods We analyzed data from the Wisconsin Registry for Alzheimer’s Prevention. First, we tested whether serial position effects were present in story recall (measured with the Wechsler Memory Scale Logical Memory Task; LMT) across individuals who were classified as cognitively unimpaired – stable, cognitively unimpaired – declining, or as having mild cognitive impairment (MCI). Results Our results showed clear serial position effects for all groups, except for delayed recall among individuals with MCI, where no primacy effect was observed. Second, we tested whether loss of primacy from immediate to delayed recall was associated with amyloid burden (as measured with PiB PET) in individuals who were cognitively unimpaired at baseline. We found that more primacy loss predicted amyloid positivity, above and beyond the LMT total score. Conclusions This report is the first to show that loss of primacy between immediate and delayed story recall is associated with amyloid burden.

Serial order in perception, memory, and action.
Logan, Gordon D.
Psychological Review, Vol 128(1), Jan, 2021. pp. 1-44.
Abstract:
This article asks whether serial order phenomena in perception, memory, and action are manifestations of a single underlying serial order process. The question is addressed empirically in two experiments that compare performance in whole report tasks that tap perception, serial recall tasks that tap memory, and copy typing tasks that tap action, using the same materials and participants. The data show similar effects across tasks that differ in magnitude, which is consistent with a single process operating under different constraints. The question is addressed theoretically by developing a Context Retrieval and Updating (CRU) theory of serial order, fitting it to the data from the two experiments, and generating predictions for 7 different summary measures of performance: list accuracy, serial position effects, transposition gradients, contiguity effects, error magnitudes, error types, and error ratios. Versions of the model that allowed sensitivity in perception and memory to decrease with serial position fit the data best and produced reasonably accurate predictions for everything but error ratios. Together, the theoretical and empirical results suggest a positive answer to the question: Serial order in perception, memory, and action may be governed by the same underlying mechanism.