What is it called when you can recall things at the beginning and end of a list?

The Recency Effect

The recency effect is a cognitive bias in which those items, ideas, or arguments that came last are remembered more clearly than those that came first. The more recently heard, the clearer something may exist in a juror's memory. This is common when information is given in lists – the last thing heard is recalled, while those at the beginning and in the middle may be forgotten. As a result, the party delivering the final closing argument – the defense – has an advantage.

The recency effect is increased when too much information is presented too quickly, and it is reduced when coupled with other tasks. With respect to jury memory, allowing note taking could also reduce both primacy and recency effects.

2.1 Recency Effects

It is fitting to begin with recency effects, an impostor that is so well known that it stars in virtually every introductory psychology textbook's discussion of memory. The problem with recency confounds in spacing studies is an old one in the literature, highlighted by Crowder's (1976) review. Specifically, because spaced items must occur in multiple locations on the list, their final presentation tends to be more recent than an equal number of massed items unless care is taken to equate the final positions. Because recent items are more easily recalled than older items, an artifactual spacing effect can be observed. One approach to solving this problem, whose discovery was attributed to Melton (1967) by Crowder, was to use primacy and recency “buffer” items that would not be tested, or just not counted for free recall. In fact, this approach was used earlier by Waugh (1962), but it is not terribly effective at controlling recency. Zimmerman (1975), for example, found an extended recency function that produced 20% higher recall for later-presented than earlier-presented items, even though he included primacy and recency buffers. He required participants to focus on only the current item, which eliminated the primacy effect, but resulted in an extended recency function.

Even in recent work, recency control has been a problem. Toppino and Bloom (2002), in their Experiment 1, replicated an experiment of Greene (1989) that compared free recall following incidental and intentional learning. The lists contained some massed and some spaced items, with spaced items of varying lag. Greene tried to control for recency biases by counterbalancing the assignment of words to quadrants of the list. The Toppino and Bloom study was virtually an exact replication of the experiment, except that it more carefully controlled recency by controlling the position of the second presentation of words instead of just the quadrant. Surprisingly, this subtle change eliminated the spacing effect for incidental learning observed by Greene. The study highlights the fact that seemingly minor recency biases can inflate or deflate the magnitude of spacing effects, altering our conclusions about the magnitude of the spacing effect—or even its presence or absence under varying conditions.

2.26.2.5 Long-Range Interitem Associations

Bjork and Whitten (1974) conducted an experiment which challenged the traditional STS-based account of recency effects in free recall. They were interested in seeing how well subjects could recall a list of word pairs under conditions designed to eliminate between-pair rehearsal. To eliminate between-pair rehearsal, they had subjects perform a difficult distractor task following the appearance of each pair, including the last one. Because the distractor was expected to displace any items in STS, Bjork and Whitten did not expect to find a recency effect. To their surprise, they found a strong recency effect, with the final few pairs being recalled better than pairs from the middle of the list. They called this the long-term recency effect. Their procedure, in which a distractor task is given following every item, including the last, is called continuous-distractor free recall. Figure 4 illustrates the continuous-distractor free recall procedure alongside the more traditional immediate and delayed free recall procedures.

The long-term recency effect has now been replicated many times using both single words and word pairs, and across delays ranging from tenths of seconds (Neath, 1993) to days (Glenberg et al., 1983). The magnitude of the long-term recency effect depends critically on both the duration of the distractor given after the last word (the retention interval) and on the duration of the distractor intervening between list words (the interpresentation interval). For a given retention interval, increasing the interpresentation interval results in more recency and better recall of the final item.

Kahana (1996) interpreted the contiguity effect as evidence for associations formed in STS. If associations are formed between items that are active together in STS (as postulated by Glanzer, 1972; Raaijmakers and Shiffrin, 1980), then this would predict the contiguity effect because nearby items spend more time together in STS than remote items. However, because a long interitem distractor should displace items in STS, the contiguity effect should be significantly attenuated in continuous-distractor free recall.

Howard and Kahana (1999) tested this hypothesis by measuring the contiguity effect in continuous-distractor free recall. Figure 5(a) illustrates the contiguity effect for interpresentation intervals ranging from 0 s (standard delayed free recall) to 16 s. As can be seen, the contiguity effect was relatively constant across this range of interpresentation intervals. This result is quantified in Figure 5(b) by fitting a power function (P = a|, |, |lag|, |, |−b) to each participant’s lag-CRP curve and using the b parameter as an estimate of the contiguity effect (the a parameter determines the overall scale of the function). Insofar as the contiguity effect is insensitive to the absolute delay between list items, it exhibits an approximate time-scale invariance. Although 16 s of a distractor had virtually no impact on the contiguity effect, the same amount of distractor activity presented at the end of the list was sufficient to eliminate the end-of-list recency effect (Figure 5(c)).

As shown in Figure 5, the contiguity effect persists even when the study items are separated by 16 s of a demanding distractor task. However, recent work shows that the contiguity effect is evident on even longer time scales. Howard et al. (2008) presented subjects with a series of lists for free recall. At the conclusion of the session, subjects were given a surprise final free recall test in which they were instructed to remember as many words as possible from the 48 study lists in any order. Howard et al. (2008) measured the contiguity effect in this final free recall period both for transitions within a list as well as between lists. They found that transitions between nearby lists were more frequent than transitions between lists that were farther apart in the experiment. This contiguity effect extended about ten lists, or several hundred seconds, extending the range over which contiguity effects are observed in free recall by a factor of ten. Moreover, this paradigm offers several potential advantages over continuous-distractor free recall. In continuous distractor free-recall, subjects have an incentive to try and rehearse items across the distractor intervals. Because the subject is only asked to recall the most recent list in the Howard et al. (2008) study, and intrusions from prior lists are scored as errors, there is no strategic reason for subjects to rehearse across lists in anticipation of the surprise final free recall test. In continuous-distractor free recall, the consistency of associations across delay intervals was inferred from observing lag-CRP curves across conditions that differed in their IPI. It is conceivable that this was due in part to different strategies across experimental conditions. In contrast, in the Howard et al. (2008) study, both within-and across-list associations were observed simultaneously during the final free recall period.

6.4 Communication strategies for effective briefings

Several psychological observations are worth considering before we look at effective briefings, especially with regard to threat management during briefings:

Primacy/recency effect – Humans have better recall for information that is presented at the start and at the end of a briefing.7

Levels of processing – Humans have better recall for information that has required a deeper level of processing. Thus, being told something requires relatively little processing on the part of the receiver whereas having to engage with that information on a semantic level (the meaning) in order to answer a question will require a deeper level of processing and so is more likely to be recalled.8 For example, rather than telling the monitoring pilot that in the event of a go-around, he needs to set up a VHF omnidirectional radio range (VOR) radial that the handling pilot can track, it would be better to ask him what he thinks would be the best navigational aid to set up in the event of a go-around. In so doing, the monitoring pilot has to check the instrument approach chart, ascertain the appropriate radial and then talk through how and when he would need to set this up. All of this requires a deeper level of processing and it is more likely that this information will be recalled later.

Context and recall – We have better recall of information that was encoded in the same environment where it will need to be retrieved.9 Fortunately, most briefings occur in the flight deck and so we can take advantage of this phenomenon.

Chronological recall – Except for introducing and re-emphasizing important points at the start and the end of the briefing, the rest of the briefing should follow a structure that matches the chronology of the sequence of actions that the briefing refers to. For example, a departure brief should cover pushback, engine start, taxi routing, take-off (and rejected take-off) and then the standard instrument departure.

Temporal contiguity and touch drills – Combining visual and verbal information at the same time aids recall, i.e. touching the relevant controls as you talk through a drill or maneuver that you may need to perform will make it more likely that it will be carried out correctly should it need to be.10

One particular guidance document concerning briefings stated that a thorough briefing should be performed regardless of how familiar the airports and procedures are or how often the crew members have flown together.11 Based on what we know about human attention, this statement, although well intentioned, may be flawed. An effective briefing must strike a balance between being comprehensive and holding the listener’s attention. Does an approach briefing for an approach into the home base of both pilots on a day when they have flown and briefed the approach already have to be as detailed as an approach into an airport that neither pilot has been to before? Carrying out a highly detailed approach briefing just for the sake of carrying out a highly detailed approach briefing is unnecessary and, ironically, introduces more risk into the flight deck because both crew members have now taken on an additional, unnecessary task. If this briefing is being carried out according to a standard script, if the other pilot has heard it before or determines that he already knows everything that is going to be said, his attention is likely to drift. To address this question of brevity versus comprehensiveness, we must first consider what the purpose of a briefing is. In short, a briefing is meant to synchronize the mental models of both pilots so that they have a shared understanding of how the aircraft is going to be maneuvered on the ground and in the air, what threats exist, how those threats are going to be managed, and what each pilot’s actions are going to be under normal and (select) abnormal conditions. If both pilots already have a shared mental model, as demonstrated by an earlier departure or arrival, cannot identify any threats, and have already talked about each pilot’s actions under normal and abnormal conditions, a departure/arrival brief could be fairly short. It may just require confirmation that the instrument approach charts are correct, the preprogrammed FMC data are valid and the relevant speed and altitude bugs are set and, for an arrival brief, a review of the go-around procedure. It is also worth noting that a briefing can be beneficial for the person leading it. By talking through the predicted sequence of events in chronological order, this can be an opportunity to mentally rehearse the actions that will be needed. Mental rehearsal has been shown to be highly beneficial in promoting recall of skilled-based actions.12

Based on the amended Threat and Error Management model (TEM2) proposed in Chapter 3 (Error Management and Standard Operating Procedures for Pilots), a departure or arrival briefing should focus on threat management and, taking account of the psychological phenomena listed in this section, a briefing should be carried out as follows:

Given that briefings often require decisions to be made, ensure that System 2 is able to dictate these decisions by carrying out briefings during low-workload periods.

Distractions and interruptions should be avoided wherever possible.

Ensure that the other pilot is ready to participate in a briefing.

Start by discussing any of the key threats that both of you have identified and back this up with the threat identification framework described in Chapter 3: low visibility, meteorological, NOTAMs, other traffic, performance, QNH, radiotelephony, systems, terrain and unfamiliarity (L-M-N-O-P-Q-R-S-T-U). Remember, this threat identification framework is just an example and can be revised and amended to include threats that are specific to your operation.

At this stage, management strategies do not need to be covered as they will be discussed when the impact of each threat is related to particular operational phases. For instance, there is little point talking about management strategies for windshear after take-off before discussing the potentially confusing taxi routing out to the runway.

Now that the major threats have been highlighted, the discussion that follows can refer back to them and to the strategies necessary to stop them affecting flight safety.

Discuss the forthcoming phases of flight in chronological order. For example, a departure briefing would cover pushback, engine start, taxi, take-off (or rejected take-off), climb and cruise; and an arrival briefing would cover descent, approach, landing (or go-around), taxi, park and shutdown.

To take advantage of the levels-of-processing phenomenon, every opportunity should be taken to make the other pilot think about what is being said. This could take the form of questions or asking him to describe his actions if a particular threat is encountered. Any procedures or maneuvers that may be needed should be rehearsed using touch drills; this will take advantage of temporal contiguity and make it more likely that these actions will be accurately carried out if the need arises.

When threats relating to a particular phase are relevant, use the avoid/buffer/contingency plan system to ensure that a threat management strategy is agreed upon.

By discussing actions that may be required in abnormal situations, the relevant production rules in procedural memory are partly activated (primed), making it more likely that they will be activated quickly should the need arise.

At the end of the briefing, take advantage of the primacy/recency effect by recapping the key points of the brief, especially the threats and the strategies that will be used to limit their effect on flight safety.

Check for understanding by asking questions and encouraging the other pilot to ask questions as well.

If time allows, unusual emergencies can also be discussed using the “What would you do if …?” format given in Chapter 2 (Information Processing).13

a Activity memories are influenced by activity features

Outcome effects show that activity memories are influenced by the structure of the activity and a broader set of factors than the processes that govern memory more generally (e.g., repetition, recency effects, delay, interference). Outcomes in themselves are memorable and characteristics such as outcome presence or absence or quality of the perceptual information provided by the outcome increase or decrease the memorability of an entire activity. Findings from studies of autobiographical memory, action memory, event memory, action concepts, and reality monitoring all show that outcome characteristics affect learning and memory of activity-related information.

These findings imply that careful attention should guide the ways in which outcomes are operationalized because these operational decisions may have an impact on how or how well an activity is remembered. Outcomes can be conceptualized in a number of different ways and each may influence memory differently, First, outcomes can involve the creation of new products or new results, or lead to no changes at all in the materials used in an activity. Making a hat or tracing letters creates some new product, whereas walking across the room or walking through the park creates only a result, a change in location. Or a person may walk in place or jump up and down, causing no perceivable outcome separate from the effects associated with the performance of the actions themselves (e.g., physiological changes). Furthermore, independent of the presence or absence of products or results, visible consequences may also be present or absent. For example, making play dough leaves behind flour and the color of the play dough on the table; tracing generates the outlines of letters; and walking in sand, either in place or to a new location, produces footprints. Would all these outcomes serve as powerful cues to the actions involved? Would some actions be cued more effectively than others? Would these effects vary for younger and older children? We do not know because the possible significance of these cues for activity memory neither has been recognized nor explored, but the findings we have summarized point to the possibility that any or all of these outcome characteristics may affect how well the activity or any of its features is remembered.

Second, outcomes are related to objects in different ways and whether objects are important in remembering actions may be related to the type of outcome produced. Objects must be involved in creating new products, but need not be present for effecting new results, such as walking across a room or sitting on the ground. Thus, objects may be more important in supporting memory when they are required to complete the action, but may be less relevant when they are present but unessential. Indeed, we would expect instruments that are used to produce outcomes to be better memory cues than objects that played no central role in the execution of the action. Furthermore, object roles may influence whether symbols representing them support memory as much as the objects themselves. For instance, play activities involving substitutions, such as gestures or pantomime, may be more effective memory supports when the objects they represent are essential to the meaning of the act than when they are not. Again, because these characteristics have not been systematically varied, we do not yet know how they contribute to activity memory. However, the findings we have reported suggest that some or all of these distinctions should have an impact on children's activity memory.

Episodic Recall Versus Word-List Recall

In the day-of-departure episode described above, the target was defined as beginning at the start of the relevant day. If this definition is accepted, then there were neither primacy nor recency effects here. Also, the same pattern (absence of primacy and recency effects) was shown across all 22 delayed memories that I chronicled. This finding provides a striking difference between episodic memory and word-list recall. In the latter, primacy effects are huge—basically, lynchpins—and recency effects tend to be quite strong too.

The finding here is not difficult to explain, however. The events involved in getting up, having breakfast, etc. are repeated with small variations each day. So the same “getting up” header must be involved across time in thousands of links to both repeated and slightly different actions, on Day 1, Day 2, Day 3,... to Day X. This is the classic pattern for producing marked similarity-based interference. Added to that negative influence, the getting-up actions are of very little interest. And breakfast suffers from the same difficulties.

An identical explanation can be offered for my abysmal recollection (from the 4-year-delay period on) of the car, bus, or plane rides that began each trip. Primacy and recency effects would have been offset by high levels of, again, similarity-based interference. Here the same cue (the header) is associated with a large number of similar events, i.e. events that show little distinctiveness, one to the other. The organization of these memories is shown below.

2.3.1 Recency Effects

If items in a distributed-practice experiment were assigned randomly to serial positions within the list, items representing greater levels of spacing would tend to occur, on the average, nearer to the ends of the list than massed items. Thus, spaced items might be remembered better than massed items, not because spacing per se produces superior memory but because spaced items benefit more than massed items from primacy and recency effects.

To control serial position effects, buffer items are usually added to the beginning and end of a list (e.g., Melton, 1970). Performance on these items is usually not analyzed. Their purpose is to absorb the primacy and recency effects, allowing the critical variables (e.g., repetition and distributed practice) to be varied in the relatively uncontaminated middle portion of the list. Unfortunately, the recency effect sometimes stretches through most of the list (e.g., Bjork & Whitten, 1974; Glenberg, Bradley, Kraus, & Renzaglia, 1983; Glenberg et al., 1980), so that buffer items alone may be insufficient to control the effect. It may be necessary to exert more stringent control, for example, by equating the items representing each distributed-practice condition with respect to the mean serial position of their last occurrences (e.g., Shaughnessy, Zimmerman, & Underwood, 1972; Underwood et al., 1976).

2.2 The Free Recall Task

Another paradigm commonly used in the early investigation of short-term memory was the free recall task, in which subjects are given a relatively long list of items and then recall them in any order they choose. When the list is recalled immediately, the subjects show greater memory for the most recent items. This ‘recency effect’ was attributed to the fact that the final items in the list, but not the earlier ones, are still in short-term memory at the termination of the list presentation. Support for this conclusion came from the observation that if presentation of the list is followed by a distractor task, then there is no recency effect, although as in the case of immediate recall there is a ‘primacy effect,’ or advantage for the initial items in the list. The explanation offered for the elimination of the recency effect with the distractor task is that the final list items are no longer in short-term memory after the distractor activity. Further support for this explanation came from finding that other variables like list length and presentation rate had differential effects on the recency and earlier sections of the serial position curve. Specifically, subjects are less likely to recall an item when it occurs in a longer list for all except the most recent list positions. Likewise, subjects are less likely to recall an item in a list presented at a faster rate for all but the recency part of the serial position curve.

69.2 The Emergence of the Concept of Short-Term Memory

The idea of memory as consisting of two main compartments, one for the current contents of consciousness and another for a permanent record of experience, has gone in and out of fashion in the past century. James (2011) coined the terms “primary memory” and “secondary memory” to refer to these two basic concepts, setting off a long-standing debate in the psychological sciences as to whether memory is best viewed a unitary or mechanistically divisible phenomenon. In the middle part of the 20th century, most theorists viewed memory as a unitary system governed by a single set of principles that were largely invariant over time (Melton, 1963; Underwood, 1957). However, in the 1960s, evidence from cognitive psychology began to point to the existence of two memory systems, one for very recent events (short-term memory) and one for events that occurred in the more distant past (long-term memory).

A critical piece of evidence supporting the “dual-store” view of memory came from studies of free recall. It was shown that when subjects are presented a list of words and must recall them in any order (free recall), performance is best for the first few items (the primacy effect) and for the last few items (the recency effect). When accuracy is plotted as a function of input order, it reveals a characteristic U-shaped (Davelaar, Goshen-Gottstein, Ashkenazi, Haarmann, & Usher, 2005; Glanzer & Cunitz, 1966; Waugh & Norman, 1965) pattern, which is referred to as the serial position curve. However, if a short delay (e.g., 10 s) is placed between stimulus presentation and recall during which subjects are required to engage in some distracting activity, the shape of the serial positive curve changed. Performance on early items (primacy) is relatively unaffected, but the recency effect is abolished (Glanzer & Cunitz, 1966; Postman & Phillips, 1965). Recency effects are attributed to the readout of the last few items in a list from short-term memory (STM), and primacy effects are reflected in the long-term memory (LTM) advantage for the first few items in a list due to the greater rehearsal devoted to those items. Moreover, recall from the long-term store requires a more effortful and slow probabilistic form of retrieval that largely depends on associative, semantic, and contextual retrieval cues than is retrieval from the short-term store. It would be remiss not to mention that this interpretation of patterns of recency effects in immediate and delayed recall as reflected in the operation of two stores has long been disputed and is complicated by the demonstration of recency effects that can span across minutes or even days (Bjork & Whitten, 1974; Crowder, 1982), although it has yet to be shown that these “long-term recency effects” have the same underlying mechanism as standard recency effects.

In summary, short-term memory is essentially a limitation of the online capacity of an information processing system. Thus, short-term memory can be viewed as a cup into which sensory information flows. The capacity of the cup is fixed and is prone to overflowing. The precise capacity of the cup varies across individuals (Unsworth & Engle, 2007), although as Miller (1956) memorably pointed out, it tends to hover around a “magical number” of 7 plus or minus 2 (but see also Cowan, 2001). When incoming information exceeds the capacity of the cup, the spillover may still be recorded in a secondary container, that is, long-term memory.

2.11.5.2.2 Knowledge statements related to cognitive-affective bases of behavior

(i)

Cognitive science (e.g., sensation and perception, attention, memory, language and spatial skills, intelligence, information processing, problem-solving, strategies for organizing information).

Theories and principles of learning (e.g., social learning, classical and operant conditioning, primacy/recency effects).

Theories of motivation (e.g., need/value approaches, cognitive choice approaches, self-regulation).

Theories of emotions.

Reciprocal interrelationships among cognitions/beliefs, behavior, affect, temperament, and mood (e.g., healthy functioning, performance anxiety, performance enhancement, job satisfaction, depression).

Influence of psychosocial factors (e.g., sex differences, family styles and characteristics, academic/occupational success) on beliefs/cognitions and behaviors.