When does intent matter for memory? Bridging perspectives with Craik.

In his commentary, Craik (see record 2023-42323-002) argued that while intentional remembering might be effective for some populations and memory tasks, these are the exception, and that intent will not benefit memory if incidental encoding induces optimal processing. While we agree on many points, we maintain that in most situations the processes induced by the intention to remember are more effective than those induced by deep semantic processing alone. We show that effects of intent appear with a variety of tasks such as free recall, cued recall, source memory, item recognition, in both mixed and pure lists, and when studying individual words, word pairs, or word-image associations. Thus, the beneficial effects of intent generalize over tasks, list-compositions, and study materials. There are also little individual differences in the effect of intent in healthy young adults-most participants (86% out of 336 participants over six experiments) show a beneficial effect. We review evidence that the intent to remember strengthens item-context bindings in episodic memory, but that such effects could be masked and not measurable in subsequent memory tests, unless intrusions are taken into account. We agree that in principle incidental encoding could induce optimal processing, but we do not find the existing evidence convincing. We provide additional novel data that directly addresses Craik's (2023) concerns and we propose ways to further investigate how intention enhances memory. We conclude with a joint statement, coauthored by Craik and ourselves, that synthesizes our converging perspectives and current understanding of the impact of intent on memory. (PsycInfo Database Record (c) 2023 APA, all rights reserved).

Intent matters: Resolving the intentional versus incidental learning paradox in episodic long-term memory.

Decades of research have established that the intent to remember information has no effect on episodic long-term memory. This claim, which is routinely taught in introductory cognitive psychology courses, is based entirely on pure-list between-subjects designs in which memory performance is equal for intentional and incidental learning groups. In the current 11 experiments, participants made semantic judgements about each word in a list but they had to remember only words presented in a specific color. We demonstrate that in such mixed-list designs there is a substantial difference between intentionally and incidentally learned items. The first four experiments show that this finding is independent of the remember cue onset relative to the semantic judgment. The remaining seven experiments test alternative explanations as to why intent only matters in mixed-list designs but not in pure-list designs-inhibition of incidentally learned items, output interference, selective relational encoding, or selective threshold-shifting. We found substantial support for the threshold-shifting account according to which the intent to remember boosts item-context associations in both mixed- and pure-list designs; however, in pure-list between-subjects designs, participants in the incidental learning group can use a lower retrieval threshold to compensate for the weaker memory traces. This led to more extralist intrusions in incidental learning groups; incidental learning groups also showed a source memory deficit. We conclude that intent always matters for long-term learning, but that the effect is masked in traditional between-subjects designs. Our results suggest that researchers need to rethink the role of intent in long-term memory. (PsycInfo Database Record (c) 2023 APA, all rights reserved).

Neutral auditory words immediately followed by painful electric shock may show reduced next-day recollection.

In this study, we investigated the effect of experimentally delivered acute pain on memory. Twenty-five participants participated in experimental sessions on consecutive days. The first session involved a categorization task to encourage memory encoding. There were two conditions, presented in randomized order, in which participants listened to a series of words, which were repeated three times. In one condition, one-third of the word items were immediately followed by a painful electrical shock. This word-shock pairing was consistent across repetition and the pain-paired items were presented unpredictably. In the other condition, all word items were not associated with pain. Response times over these repeated presentations were assessed for differences. Explicit memory was tested the following day, employing a Remember-Know assessment of word recognition, with no shocks employed. We found evidence that recollection may be reduced for pain-paired words, as the proportion of correct Remember responses (out of total correct responses) was significantly lower. There were no significant reductions in memory for non-pain items that followed painful stimulation after a period of several seconds. Consistent with the experience of pain consuming working memory resources, we theorize that painful shocks interrupt memory encoding for the immediately preceding experimental items, due to a shift in attention away from the word item.

Memory resources recover gradually over time: The effects of word frequency, presentation rate, and list composition on binding errors and mnemonic precision in source memory.

Normative word frequency has played a key role in the study of human memory, but there is little agreement as to the mechanism responsible for its effects. To determine whether word frequency affects binding probability or memory precision, we used a continuous reproduction task to examine working memory for spatial positions of words. In three experiments, after studying a list of five words, participants had to report the spatial location of one of them on a circle. Across experiments we varied word frequency, presentation rate, and the proportion of low-frequency words on each trial. A mixture model dissociated memory precision, binding failure, and guessing rate parameters from the continuous distribution of errors. On trials that contained only low- or only high-frequency words, low-frequency words led to a greater degree of error in recalling the associated location. This was due to a higher word-location binding failure and not due to differences in memory precision or guessing rates. Slowing down the presentation rate eliminated the word frequency effect by reducing binding failures for low-frequency words. Mixing frequencies in a single trial hurt high-frequency and helped low-frequency words. These findings support the idea that word frequency can lead to both positive and negative mnemonic effects depending on a trade-off between an HF encoding advantage and a LF retrieval cue advantage. We suggest that (1) low-frequency words require more resources for binding, (2) that these resources recover gradually over time, and that (3) binding fails when these resources are insufficient. (PsycInfo Database Record (c) 2022 APA, all rights reserved).

Midazolam and Ketamine Produce Distinct Neural Changes in Memory, Pain, and Fear Networks during Pain.

BACKGROUND: Despite the well-known clinical effects of midazolam and ketamine, including sedation and memory impairment, the neural mechanisms of these distinct drugs in humans are incompletely understood. The authors hypothesized that both drugs would decrease recollection memory, task-related brain activity, and long-range connectivity between components of the brain systems for memory encoding, pain processing, and fear learning. METHODS: In this randomized within-subject crossover study of 26 healthy adults, the authors used behavioral measures and functional magnetic resonance imaging to study these two anesthetics, at sedative doses, in an experimental memory paradigm using periodic pain. The primary outcome, recollection memory performance, was quantified with d' (a difference of z scores between successful recognition versus false identifications). Secondary outcomes were familiarity memory performance, serial task response times, task-related brain responses, and underlying brain connectivity from 17 preselected anatomical seed regions. All measures were determined under saline and steady-state concentrations of the drugs. RESULTS: Recollection memory was reduced under midazolam (median [95% CI], d' = 0.73 [0.43 to 1.02]) compared with saline (d' = 1.78 [1.61 to 1.96]) and ketamine (d' = 1.55 [1.12 to 1.97]; P < 0.0001). Task-related brain activity was detected under saline in areas involved in memory, pain, and fear, particularly the hippocampus, insula, and amygdala. Compared with saline, midazolam increased functional connectivity to 20 brain areas and decreased to 8, from seed regions in the precuneus, posterior cingulate, and left insula. Compared with saline, ketamine decreased connectivity to 17 brain areas and increased to 2, from 8 seed regions including the hippocampus, parahippocampus, amygdala, and anterior and primary somatosensory cortex. CONCLUSIONS: Painful stimulation during light sedation with midazolam, but not ketamine, can be accompanied by increased coherence in brain connectivity, even though details are less likely to be recollected as explicit memories.

Validation of the Levenson Self-Report Psychopathy Scale in Bulgarian Substance-Dependent Individuals.

The co-occurrence of psychopathy and substance use disorders (SUDs) is associated with higher relapse rates and increased risk of violent offending. Studies on the validity of psychopathy measures in community samples and substance-dependent individuals (SDIs) are scarce. The aim of the current study was to examine the psychometric properties of the Levenson Self-Report Psychopathy Scale (LSRP) in a sample of Bulgarian SDIs and non-dependent controls. We tested 615 participants: 106 heroin users, 91 amphetamine users, 123 polysubstance users, and 295 controls. Confirmatory factor analyses replicated the tri-factor structure of the LSRP (egocentric, antisocial, callous). The scale demonstrated acceptable reliability and validity. SDIs scored significantly higher than controls on the total scale and subscales of the LSRP, indicating good discriminant validity. Overall, results indicate that the LSRP is a valid instrument for measuring psychopathy in Bulgarian community samples.

Greater discrimination difficulty during perceptual learning leads to stronger and more distinct representations.

Despite the conventional wisdom that it is more difficult to find a target among similar distractors, this study demonstrates that this disadvantage is short-lived, and that high target-to-distractor (TD) similarity during visual search training can have beneficial effects for learning. Participants with no prior knowledge of Chinese performed 12 hour-long sessions over 4 weeks, where they had to find a briefly presented target character among a set of distractors. At the beginning of the experiment, high TD similarity hurt performance, but the effect reversed during the first session and remained positive throughout the remaining sessions. This effect was due primarily to reducing false alarms on trials in which the target was absent from the search display. In addition, making an error on a trial with a specific character was associated with slower visual search response times on the subsequent repetition of the character, suggesting that participants paid more attention in encoding the characters after false alarms. Finally, the benefit of high TD similarity during visual search training transferred to a subsequent N-back working-memory task. These results suggest that greater discrimination difficulty likely induces stronger and more distinct representations of each character.

Frequency effects on memory: A resource-limited theory.

We present a review of frequency effects in memory, accompanied by a theory of memory, according to which the storage of new information in long-term memory (LTM) depletes a limited pool of working memory (WM) resources as an inverse function of item strength. We support the theory by showing that items with stronger representations in LTM (e.g., high frequency items) are easier to store, bind to context, and bind to one another; that WM resources are involved in storage and retrieval from LTM; that WM performance is better for stronger, more familiar stimuli. We present a novel analysis of preceding item strength, in which we show from nine existing studies that memory for an item is higher if during study it was preceded by a stronger item (e.g., a high frequency word). This effect is cumulative (the more prior items are of high frequency, the better), continuous (memory proportional to word frequency of preceding item), interacts with current item strength (larger for weaker items), and interacts with lag (decreases as the lag between the current and prior study item increases). A computational model that implements the theory is presented, which accounts for these effects. We discuss related phenomena that the model/theory can explain. (PsycINFO Database Record (c) 2019 APA, all rights reserved).

Forgetting Is a Feature, Not a Bug: Intentionally Forgetting Some Things Helps Us Remember Others by Freeing Up Working Memory Resources.

In the present study, we used an item-method directed-forgetting paradigm to test whether instructions to forget or remember one item affect memory for subsequently studied items. In two experiments (Ns = 138 and 33, respectively), recall was higher when a word pair was preceded during study by a to-be-forgotten word pair. This effect was cumulative: Performance increased when more preceding study items were to be forgotten. The effect decreased when memory was conditioned on instructions for items appearing farther back in the study list. Experiment 2 used a dual-task paradigm that suppressed, during encoding, verbal rehearsal or attentional refreshing. Neither task removed the effect, ruling out that rehearsal or attentional borrowing is responsible for the advantage conferred from previous to-be-forgotten items. We propose that memory formation depletes a limited resource that recovers over time and that to-be-forgotten items consume fewer resources, leaving more resources available for storing subsequent items. A computational model implementing the theory provided excellent fits to the data.

Semantic knowledge influences whether novel episodic associations are represented symmetrically or asymmetrically.

We provide new evidence concerning two opposing views of episodic associations: The independent-association hypothesis posits that associations are unidirectional and separately modifiable links (A→B and A←B); in contrast, the associative-symmetry hypothesis proposes that a single, bidirectional association exists between A and B (A↔B). We used a novel method to demonstrate that whether or not episodic associations are symmetric depends on whether there is a preexisting semantic relationship between A and B. In two experiments, participants studied 30 semantically unrelated and 30 semantically related pairs intermixed in a single list and then performed a series of up to eight cued-recall test cycles. All pairs were tested in each cycle, and the testing direction (A-? or B-?) alternated between cycles. Unrelated pairs exhibited associative symmetry-that is, accuracy and response times improved gradually on each test-suggesting that testing in both directions strengthened the same association. In contrast, semantically related pairs exhibited a stair-like pattern, in which performance did not change from odd to even tests when the test direction changed; it only improved between tests in the same direction. We concluded that episodic associations can have either a single bidirectional representation or separate directional representations, depending on the semantic relatedness of their constituent items.

Practices and pitfalls in inferring neural representations.

A key challenge for cognitive neuroscience is deciphering the representational schemes of the brain. Stimulus-feature-based encoding models are becoming increasingly popular for inferring the dimensions of neural representational spaces from stimulus-feature spaces. We argue that such inferences are not always valid because successful prediction can occur even if the two representational spaces use different, but correlated, representational schemes. We support this claim with three simulations in which we achieved high prediction accuracy despite systematic differences in the geometries and dimensions of the underlying representations. Detailed analysis of the encoding models' predictions showed systematic deviations from ground-truth, indicating that high prediction accuracy is insufficient for making representational inferences. This fallacy applies to the prediction of actual neural patterns from stimulus-feature spaces and we urge caution in inferring the nature of the neural code from such methods. We discuss ways to overcome these inferential limitations, including model comparison, absolute model performance, visualization techniques and attentional modulation.

Item strength affects working memory capacity.

Do the processing and online manipulation of stimuli that are less familiar require more working memory (WM) resources? Is it more difficult to solve demanding problems when the symbols involved are less rather than more familiar? We explored these questions with a dual-task paradigm in which subjects had to solve algebra problems of different complexities while simultaneously holding novel symbol-digit associations in WM. The symbols were previously unknown Chinese characters, whose familiarity was manipulated by differential training frequency with a visual search task for nine hour-long sessions over 3 weeks. Subsequently, subjects solved equations that required one or two transformations. Before each trial, two different integers were assigned to two different Chinese characters of the same training frequency. Half of the time, those characters were present as variables in the equation and had to be substituted for the corresponding digits. After attempting to solve the equation, subjects had to recognize which two characters were shown immediately before that trial and to recall the integer associated with each. Solution accuracy and response times were better when the problems required one transformation only; variable substitution was not required; or the Chinese characters were high frequency. The effects of stimulus familiarity increased as the WM demands of the equation increased. Character-digit associations were also recalled less well with low-frequency characters. These results provide strong support that WM capacity depends not only on the number of chunks of information one is attempting to process but also on their strength or familiarity.

The relational luring effect: Retrieval of relational information during associative recognition.

Here we argue that semantic relations (e.g., works in: nurse-hospital) have abstract independent representations in long-term memory (LTM) and that the same representation is accessed by all exemplars of a specific relation. We present evidence from 2 associative recognition experiments that uncovered a novel relational luring effect (RLE) in recognition memory. Participants studied word pairs, and then discriminated between intact (old) pairs and recombined lures. In the first experiment participants responded more slowly to lures that were relationally similar (table-cloth) to studied pairs (floor-carpet), in contrast to relationally dissimilar lures (pipe-water). Experiment 2 extended the RLE by showing a continuous effect of relational lure strength on recognition times (RTs), false alarms, and hits. It used a continuous pair recognition task, where each recombined lure or target could be preceded by 0, 1, 2, 3 or 4 different exemplars of the same relation. RTs and false alarms increased linearly with the number of different previously seen relationally similar pairs. Moreover, more typical exemplars of a given relation lead to a stronger RLE. Finally, hits for intact pairs also rose with the number of previously studied different relational instances. These results suggest that semantic relations exist as independent representations in LTM and that during associative recognition these representations can be a spurious source of familiarity. We discuss the implications of the RLE for current models of semantic and episodic memory, unitization in associative recognition, analogical reasoning and retrieval, as well as constructive memory research. (PsycINFO Database Record

Cortical Networks Involved in Memory for Temporal Order.

We examined the neurobiological basis of temporal resetting, an aspect of temporal order memory, using a version of the delayed-match-to-multiple-sample task. While in an fMRI scanner, participants evaluated whether an item was novel or whether it had appeared before or after a reset event that signified the start of a new block of trials. Participants responded "old" to items that were repeated within the current block and "new" to both novel items and items that had last appeared before the reset event (pseudonew items). Medial-temporal, prefrontal, and occipital regions responded to absolute novelty of the stimulus-they differentiated between novel items and previously seen items, but not between old and pseudonew items. Activation for pseudonew items in the frontopolar and parietal regions, in contrast, was intermediate between old and new items. The posterior cingulate cortex extending to precuneus was the only region that showed complete temporal resetting, and its activation reflected whether an item was new or old according to the task instructions regardless of its familiarity. There was also a significant Condition (old/pseudonew) × Familiarity (second/third presentations) interaction effect on behavioral and neural measures. For pseudonew items, greater familiarity decreased response accuracy, increased RTs, increased ACC activation, and increased functional connectivity between ACC and the left frontal pole. The reverse was observed for old items. On the basis of these results, we propose a theoretical framework in which temporal resetting relies on an episodic retrieval network that is modulated by cognitive control and conflict resolution.

Building knowledge requires bricks, not sand: The critical role of familiar constituents in learning.

Despite vast efforts to better understand human learning, some principles have been overlooked; specifically, that less familiar stimuli are more difficult to combine to create new knowledge and that this is because less familiar stimuli consume more working memory resources. Participants previously unfamiliar with Chinese characters were trained to discriminate visually similar characters during a visual search task over the course of a month, during which half of the characters appeared much more frequently. Ability to form associations involving these characters was tested via cued recall for novel associations consisting of two Chinese characters and an English word. Each week performance improved on the cued-recall task. Crucially, however, even though all Chinese character pairs were novel each week, those pairs consisting of more familiar characters were more easily learned. Performance on a working-memory task was better for more familiar stimuli, consistent with the claim that familiar stimuli consume fewer working memory resources. These findings have implications for optimal instruction, including second language learning.

Unintentional and efficient relational priming.

If relational priming is responsible for unintentional analogical reasoning, as has been suggested, it too should occur unintentionally. However, results from previous studies are inconclusive - studies that use the sensicality task usually demonstrate unintentional priming, while lexical decision tasks have failed to capture the effect without explicitly instructing participants to note and use the relational similarity in the stimuli. We discuss possible reasons for these contradictory results. Based on this discussion, we aimed to maximize our chances to find an effect by ensuring that the primes and targets elicit the same processing, by using a longer SOA, suitable for the more complex nature of the task, and by ensuring that the stimuli are good exemplars of the relations that hold between them. We present two experiments that obtained unintentional and efficient priming of relations with a lexical decision task. Participants made a lexical decision for a target pair of words more quickly when it was preceded by a similarly related pair of words, compared to an unrelated pair. Participants were not instructed to note and use the relations. Experiment 2 extended those results by showing that the effect is present even when executive working memory resources are occupied by a secondary task. Even though it turned out that the base pairs differed on semantic similarity, co-occurrence and imageability between the two conditions, these differences were not responsible for the effect. Thus, relations can be primed unintentionally and efficiently, even when relational integration is not necessitated by task demands.