Does retrieval practice depend on semantic cues? Assessing the fuzzy trace account of the testing effect

Retrieval practice enhances long-term retention more than restudying; a phenomenon called the testing effect. The fuzzy trace explanation predicts that a testing effect will already emerge after a short interval when participants are solely provided with semantic cues in the final test. In the present study, we assessed this explanation by gradually reducing the surface features overlap between cues in the learning phase and the final recognition test. In all five experiments, participants in the control/word condition received as final test cues the same words as in the learning phase. The experimental final test cues consisted of scrambled words, words in a new context, scrambled words in a new context (Experiment 1), synonyms (Experiment 2), or images (Experiments 3, 4a, 4b). A short-term testing effect was only observed for the image final test cues. These results do not provide strong support for the fuzzy trace explanation of the testing effect.     

Support for an explanation of the guidance effect in motor skill learning

The authors investigated whether the knowledge of results (KR) schedule influences the extent to which intrinsic feedback is noticed and used. Fifty-six participants received KR that was either delayed over 2 trials (Delay-2) or provided directly after each trial (Delay-0) during 160 trials of an unfamiliar aiming task. No-KR retention tests were given after 80 trials and 1 min and 24 hr after the end of acquisition. After retention, all participants were questioned about their use of intrinsic feedback during practice and whether those sources changed as a function of practice. The Delay-2 group performed significantly less accurately on the 1st and last blocks of acquisition trials but showed a significantly smaller performance decline from acquisition to retention. Moreover, the Delay-2 group noticed and used a greater variety of intrinsic feedback sources and its members were more likely to report that their usage changed with practice.     

Measurement of trace strength in memory for pictures

Four experiments using a yes-no recognition task with snapshots examined (1) the effect of presenting not one but two items simultaneously, either both targets or both distractors, for a single judgment at a retention test trial; (2) the rate of forgetting; (3) the interaction between retention interval and the exposure duration at acquisition; (4) acquisition as a function of the number of times a picture was presented. In each case performance was assessed by calculating the discriminability index d'. The results supported the hypotheses that trace strength is lognormally distributed, that forgetting is exponential, and that in acquisition trace strength is a linear function of the number of presentations.     

Trace resistance and the decay of long-term memory

A theory of storage in long-term memory is described which characterizes the trace by two properties: strength and resistance. The theory makes four assumptions: (a) The rate of decay of strength equals the force on the trace divided by the resistance. (b) Force is proportional to trace strength and to the similarity of current traces to the previously established trace. (c) Resistance increases as the square root of trace age. (d) The resistance of a trace transfers completely to subsequent increments. The theory accounts for long-term retention functions over delays from 1 min to 2 yr, long retrograde amnesia, unlearning, effects of multiple learning trials and spacing of practice, and possibly recency judgments and retention functions following relearning.     

Role of Constant,Random and Blocked Practice in an Electromyography-Based Oral Motor Learning Task

Purpose: The role of principles of motor learning (PMLs) in speech has received much attention in the past decade. Oral motor learning, however, has not received similar consideration. This study evaluated the role of three practice conditions in an oral motor tracking task.

Method: Forty-five healthy adult participants were randomly and equally assigned to one of three practice conditions (constant, blocked, and random) and participated in an electromyography-based task. The study consisted of four sessions, at one session a day for four consecutive days. The first three days sessions included a practice phase, with immediate visual feedback, and an immediate retention phase, without visual feedback. The fourth session did not include practice, but only delayed retention testing, lasting 10–15 minutes, without visual feedback.

Results: Random group participants performed better than participants in constant and blocked practice conditions on all the four days. Constant group participants demonstrated superior learning over blocked group participants only on day 4.

Conclusion: Findings indicate that random practice facilitates oral motor learning, which is in line with limb/speech motor learning literature. Future research should systematically investigate the outcomes of random practice as a function of different oral and speech-based tasks.     

Snoddy (1926) revisited: time scales of motor learning

The authors investigated the time scales of the learning of a mirror-tracing task to reexamine G. S. Snoddy's (1926) original claim and the received theoretical view (A. Newell & P. S. Rosenbloom, 1981) that motor learning follows a power law. Adult participants (N = 16) learned the tracing task in either a normal or a reversed visual-image condition over 5 consecutive days of practice and then performed 1 day of practice 1 week later and again 1 month later. The reversed-image group's performance was poorer than that of the normal-image group throughout the practice. An exponential was the best fitting function on individual data, but the power-law function was the best fit on the group-averaged data. The findings provided preliminary evidence that 2 characteristic time scales, (a) fast, dominated by warm-up, and (b) slow, dominated by persistent change, capture individuals' performance in the learning of the mirror-tracing task.     

The power law repealed: The case for an exponential law of practice

The power function is treated as the law relating response time to practice trials. However, the evidence for a power law is flawed, because it is based on averaged data. We report a survey that assessed the form of the practice function for individual learners and learning conditions in paradigms that have shaped theories of skill acquisition. We fit power and exponential functions to 40 sets of data representing 7,910 learning series from 475 subjects in 24 experiments. The exponential function fit better than the power function in all the unaveraged data sets. Averaging produced a bias in favor of the power function. A new practice function based on the exponential, the APEX function, fit better than a power function with an extra, preexperimental practice parameter. Clearly, the best candidate for the law of practice is the exponential or APEX function, not the generally accepted power function. The theoretical implications are discussed.     

Practice and forgetting effects on vocabulary memory: an activation-based model of the spacing effect

An experiment was performed to investigate the effects of practice and spacing on retention of Japanese–English vocabulary paired associates. The relative benefit of spacing increased with increased practice and with longer retention intervals. Data were fitted with an activation-based memory model, which proposes that each time an item is practiced it receives an increment of strength but that these increments decay as a power function of time. The rate of decay for each presentation depended on the activation at the time of the presentation. This mechanism limits long-term benefits from further practice at higher levels of activation and produces the spacing effect and its observed interactions with practice and retention interval. The model was compared with another model of the spacing effect (Raaijmakers, 2003) and was fit to some results from the literature on spacing and memory.     

Identity practices, ingroup projection, and the evaluation of subgroups: a study among Turkish-Dutch Sunnis

This research focuses on religious subgroup evaluations by examining the attitude of Turkish-Dutch Sunni Muslims towards Alevi and Shiite Muslims. Following the Ingroup Projection Model, it was expected that Sunni participants who practice Islam will project their self-defining subgroup practices on the superordinate Muslim category, which will be related to more ingroup bias towards Alevis, a Muslim subgroup that performs different religious practices. Two studies yielded consistent evidence that practicing Islam increased ingroup bias towards Alevis. Furthermore, in Study 2, we found evidence that the effect of practicing Islam on ingroup bias was mediated by relative ingroup prototypicality (RIP). Moreover, practicing Islam did not affect RIP in relation to Shiites who perform the same religious practices that we examined. These findings support the Ingroup Projection Model.     

Divided attention: An undesirable difficulty in memory retention

How can we improve memory retention? A large body of research has suggested that difficulty encountered during learning, such as when practice sessions are distributed rather than massed, can enhance later memory performance (see R. A. Bjork & E. L. Bjork, 1992). Here, we investigated whether divided attention during retrieval practice can also constitute a desirable difficulty. Following two initial study phases and one test phase with Swahili–English word pairs (e.g., vuvi–snake), we manipulated whether items were tested again under full or divided attention. Two days later, participants were brought back for a final cued-recall test (e.g., vuvi–?). Across three experiments (combined N = 122), we found no evidence that dividing attention while practicing retrieval enhances memory retention. This finding raises the question of why many types of difficulty during practice do improve long-term retention, but dividing attention does not.     

Can the relationship between tangential velocity and radius of curvature explain motor constancy?

To address contributions of speed, efficiency, radius of curvature and joint complexity to the strength of the lawful relationship between tangential velocity and radius of curvature (power law), an experiment considered the strength of the power law when participants were instructed to perform circling movements using the elbow, finger, shoulder, or wrist. Five participants performed circling motions in a vertical plane upon a Smartboard that sampled finger tip position at 200Hz. Page's L tested whether the strength of the power law could be predicted by: (1) speed; (2) submovements; (3) joint complexity; (4) radius of curvature. A second experiment considered the strength of the power law when six participants were instructed to perform circling movements of different sizes (large, medium, and small) using their shoulders. Movement speed or efficiency could not explain the strength of the power law, instead the power law was stronger for movements with a smaller radius of curvature or fewer joints. The strength of the power law varied with effector, questioning the role of the power law in motor constancy.     

线索强度对提取练习效应的影响机制：来自ERP的证据

运用事件相关电位技术,探讨提取练习和精细加工在不同线索强度上的加工方式有何不同。结果显示：强线索词对下,二者的相继记忆效应未出现显著性的分离,出现500-700ms额叶、中央分布的模式;弱线索词对下,二者的相继记忆效应出现分离,提取条件500-700ms,700-1000ms观察到与晚期顶叶成分相似的相继记忆效应,精细加工下并没有。结果表明：提取强线索词时个体的加工方式与精细加工类似,提取弱线索词时与精细加工不同,支持情境背景理论。     

Attention focusing instructions and coordination bias: Implications for learning a novel bimanual task

Four groups learnt a novel bimanual coordination movement pattern under instructions designed to manipulate focus of attention. It was predicted that instructions directing attention onto the effects of the action would facilitate learning. Three groups received demonstrations of the required 90° relative phase movement. Two of the demonstration groups also received instruction directing attention either towards the feedback (EXTERNAL), or the relationship between their arm movements and the feedback (RELATION). The third group received no attention directing instructions (DEMO). A final group was only provided with goal relevant feedback (NO DEMO). A scanning task enabled coordination bias to be assessed pre-practice. This was conducted to ensure task novelty and assign participants equally across groups based on strength of bias to in- and/or anti-phase. Acquisition rate was slower for the DEMO only group, especially compared to the EXTERNAL group. Additionally, participants biased to in-phase (as compared to anti-phase) during the scanning trial also showed high error early in practice. These differences remained in retention. Irrespective of feedback condition the DEMO group evidenced the most error in retention. However, all groups were affected by the removal of on-line feedback, although the attention-directing instructions provided during practice somewhat decreased the negative effects associated with feedback removal. Overall, the in-phase-biased participants were most affected by withdrawal of feedback. It was concluded that movement demonstrations alone do not facilitate learning of a novel coordination task, unless additional goal-directed instruction is provided. Additionally, individual differences in coordination bias pre-practice can be used to predict learning rate and quality.     

Movement substructures change as a function of practice in children and adults

An experiment is reported in which participants at 6 (n = 20), 9 (n = 20), and 24 years (n = 20) of age either received or did not receive practice on a rapid aiming task using the arm and hand. The purpose of the experiment was to document the changes in movement substructures (in addition to movement time) as a function of practice. After receiving 10 baseline trials, subjects in the practice groups received 30 practice trials followed by 10 retention trials on each of 5 days, while subjects in the no-practice group had only baseline and retention trials. Retention-only trials were divided into primary (reflecting the ballistic controlled part of the movement) and secondary (reflecting corrective movement adjustments) submovements. In addition, jerk (the 3rd derivative of movement displacement) was calculated as an estimate of the smoothness of the movement. Participants increased the primary submovement as a function of practice; however, the increases were substantially larger in the children (25-30%) than in the adults (10%). Participants also decreased jerk as a function of practice and the decreases were greater in children than in adults. The results suggest that with practice the primary submovement is lengthened so that it ends nearer the target, especially in children. Associated with the primary submovement covering a larger percentage of the movement length and time, movements became smoother.     

Practice increases the efficiency of evidence accumulation in perceptual choice

Most models of choice response time base decisions on evidence accumulated over time. A fundamental distinction among these models concerns whether each piece of evidence is equally weighted (lossless accumulation) or unequally weighted (leaky accumulation). The authors tested a hypothesis derived from A. Heathcote and S. Brown's (2002) self-exciting expert competitor (SEEXC) model of skill acquisition: that evidence accumulation becomes less leaky with practice. The hypothesis was supported by observation that the effects of prime stimuli increased with practice. The authors used metacontrast masked primes, which could not be consciously discriminated by most participants, to avoid methodological problems associated with conscious strategy changes. The form of the law of practice in the data is also shown to be consistent with the SEEXC model.     

Scheduling observational and physical practice: influence on the coding of simple motor sequences

The main purpose of the present experiment was to determine the coordinate system used in the development of movement codes when observational and physical practice are scheduled across practice sessions. The task was to reproduce a 1,300-ms spatial-temporal pattern of elbow flexions and extensions. An intermanual transfer paradigm with a retention test and two effector (contralateral limb) transfer tests was used. The mirror effector transfer test required the same pattern of homologous muscle activation and sequence of limb joint angles as that performed or observed during practice, and the non-mirror effector transfer test required the same spatial pattern movements as that performed or observed. The test results following the first acquisition session replicated the findings of Gruetzmacher, Panzer, Blandin, and Shea (2011) . The results following the second acquisition session indicated a strong advantage for participants who received physical practice in both practice sessions or received observational practice followed by physical practice. This advantage was found on both the retention and the mirror transfer tests compared to the non-mirror transfer test. These results demonstrate that codes based in motor coordinates can be developed relatively quickly and effectively for a simple spatial-temporal movement sequence when participants are provided with physical practice or observation followed by physical practice, but physical practice followed by observational practice or observational practice alone limits the development of codes based in motor coordinates.     

Adaptive memory: the comparative value of survival processing

We recently proposed that human memory systems are "tuned" to remember information that is processed for survival, perhaps as a result of fitness advantages accrued in the ancestral past. This proposal was supported by experiments in which participants showed superior memory when words were rated for survival relevance, at least relative to when words received other forms of deep processing. The current experiments tested the mettle of survival memory by pitting survival processing against conditions that are universally accepted as producing excellent retention, including conditions in which participants rated words for imagery, pleasantness, and self-reference; participants also generated words, studied words with the intention of learning them, or rated words for relevance to a contextually rich (but non-survival-related) scenario. Survival processing yielded the best retention, which suggests that it may be one of the best encoding procedures yet discovered in the memory field.     

Judgments of learning are significantly higher following feedback on relatively good versus relatively poor trials despite no actual learning differences

Studies have consistently shown that prospective metacognitive judgments of learning are often inaccurate because humans mistakenly interpret current performance levels as valid indices of learning. These metacognitive discrepancies are strongly related to conditions of practice. Here, we examined how the type of feedback (after good versus poor trials) received during practice and awareness (aware versus unaware) of this manipulation affected judgments of learning and actual learning. After each six-trial block, participants received feedback on their three best trials or three worst trials and half of the participants were made explicitly aware of the type of feedback they received while the other half were unaware. Judgments of learning were made at the end of each six-trial block and before the 24-h retention test. Results indicated no motor performance differences between groups in practice or retention; however, receiving feedback on relatively good compared to relatively poor trials resulted in significantly higher judgments of learning in practice and retention, irrespective of awareness. These results suggest that KR on relatively good versus relatively poor trials can have dissociable effects on judgments of learning in the absence of actual learning differences, even when participants are made aware of their feedback manipulation.     

Contextual interference effect on acquisition and retention of pistol-shooting skills

The effects of contextual interference on learning pistol-shooting skills in a natural training environment were examined. The shooting skills consisted of three "stages" with different requirements for the skill variations commonly used in the field. 12 participants were randomly assigned into one of two practice conditions, blocked vs serial. Following a 20-min. safety and skill instructional session, Blocked group practiced 10 trials in a row at each stage, while Serial group performed 5 trials in a row for each of the three stages and then repeated the cycle. Both groups completed a total of 30 practice trials over the three stages. A 10-min. rest interval was provided prior to a retention test which included 9 trials (3 trials at each stage in a blocked format). Results based on the data of Stage III, the most complex skill among the three stages, showed a pattern consistent with previous findings that practicing in the serial schedule depressed performance during initial training but maintained the performance better at retention, relative to the blocked practice.