Recurrent involuntary memories and mind wandering are related but distinct.

Spontaneous thought is common in daily life, and includes recurrent involuntary autobiographical memories (IAMs; memories retrieved unintentionally and repetitively) and mind wandering (MW). Both recurrent IAMs and MW are often unintentional or unconstrained, and both predict symptoms of mental health disorders. However, not all MW is unintentional, and not all IAMs are unconstrained. To what extent do recurrent IAMs and MW converge versus diverge? Undergraduates (N = 2,701) completed self-report measures of recurrent IAMs, trait MW, and psychopathology (i.e., PTSD, depression, anxiety). Regressions indicated that recurrent IAMs were significantly associated with spontaneous MW, but not deliberate MW. Further, both spontaneous MW and recurrent IAMs had unique relationships with disorder symptoms. Results suggest that recurrent IAMs are related to MW to the extent that recurrent IAMs are spontaneous. Conversely, recurrent IAMs are distinct from MW to the extent that recurrent IAMs' associations with disorder symptoms could not be solely explained by trait MW (and vice versa). This work highlights related, but distinguishable, forms of spontaneous thought and their transdiagnostic links with psychopathology.

Brain regions supporting retrieval of words drawn at encoding: fMRI evidence for multimodal reactivation.

Memory for words that are drawn or sketched by the participant, rather than written, during encoding is typically superior. While this drawing benefit has been reliably demonstrated in recent years, there has yet to be an investigation of its neural basis. Here, we asked participants to either create drawings, repeatedly write, or list physical characteristics depicting each target word during encoding. Participants then completed a recognition memory test for target words while undergoing functional magnetic resonance imaging (fMRI). Behavioural results showed memory was significantly higher for words drawn than written, replicating the typical drawing effect. Memory for words whose physical characteristics were listed at encoding was also higher than for those written repeatedly, but lower than for those drawn. Voxel-wise analyses of fMRI data revealed two distributed sets of brain regions more active for items drawn relative to written, the left angular gyrus (BA 39) and bilateral frontal (BA 10) regions, suggesting integration and self-referential processing during retrieval of drawn words. Brain-behaviour correlation analyses showed that the size of one's memory benefit for words drawn relative to written at encoding was positively correlated with activation in brain regions linked to visual representation and imagery (BA 17 and cuneus) and motor planning (premotor and supplementary motor areas; BA 6). This study suggests that drawing benefits memory by coactivating multiple sensory traces. Target words drawn during encoding are subsequently remembered by re-engaging visual, motoric, and semantic representations.

How varying cue duration influences item-method directed forgetting: A novel selective retrieval interpretation.

A series of four experiments tested the assumptions of the most prominent and longstanding account of item-method directed forgetting: the selective rehearsal account. In the item-method directed forgetting paradigm, each presented item is followed by its own instructional cue during the study phase - either to-be-forgotten (F) or to-be-remembered (R). On a subsequent test, memory is poorer for F items than for R items. To clarify the mechanism underlying memory performance, we manipulated the time available for rehearsal, examining instructional cue durations of 1 s, 5 s, and 10 s. Experiments 1a and 1b, where the order of cue durations was randomized, showed no effect of cue duration on item recognition of unrelated single words, for either R or F items. Experiment 2, using unrelated word pairs, again showed no effect of randomized cue duration, this time on associative recognition. Experiments 3 and 4 blocked cue duration and showed equivalent increases in recognition of both R and F single words and word pairs with increasing cue duration. We suggest that any post-cue rehearsal is carried out only when cue duration is predictable, and that such limited rehearsal is equally likely for F items and R items. The consistently better memory for R items than for F items across cue duration depends on selective retrieval involving (1) a rapid retrieval check engaged for R items only and (2) a rapid removal process implemented for F items only.

Effectiveness of production and drawing as encoding techniques on recall using mixed- and pure-list designs.

We compared the benefit of production and drawing on recall of concrete and abstract words, using mixed- and pure-list designs. We varied stimulus and list types to examine whether the memory benefit from these strategies was sustained across these manipulations. For all experiments, the memory retrieval task was free recall. In Experiment 1, participants studied concrete and abstract words sequentially, with prompts to either silently-read, read aloud, write, or draw each target (intermixed). Reading aloud, writing, and drawing improved recall compared to silent reading, with drawing leading to the largest boost. Performance, however, was at floor in all but the drawing condition. In Experiment 2, the number of targets was reduced, and each strategy (between-subjects) was compared to silent-reading. We eliminated floor effects and replicated results from Experiment 1. In Experiment 3, we manipulated strategy in a pure-list-design. The drawing benefit was maintained while that from production was eliminated. In all experiments, recall was higher for concrete than abstract words that were drawn; no such effect was found for words produced. Results suggest that drawing facilitates memory by enhancing semantic elaboration, whereas the production benefit is largely perceptually based. Importantly, the memory benefit conferred by drawing at encoding, unlike production, cannot be explained by a distinctiveness account as it was relatively unaffected by study design.

Long-term cognitive and affective consequences of mild traumatic brain injury: comparison with older adults.

OBJECTIVE: Memory and affective processing were compared in young adults with a remote mild traumatic brain injury (mTBI), to healthy younger and older adults. We evaluated memory performance when encoding was done under multi-tasking (divided attention) conditions, likely to exacerbate cognitive and psychological symptoms in mTBI. METHODS: Participants studied pairs of unrelated words under either full or divided attention conditions. Memory for single words (item memory) and for pairs of words (associative memory) was then assessed in sequential independent recognition tests, under full attention. RESULTS: Associative memory was poorer than item memory, and worse when encoding was done under divided than full attention. The decline in recognition accuracy from full to divided attention conditions on the associative memory test was significantly greater in mTBI compared to young adults and was similar in magnitude to that observed in older adults under full attention. Self-reported mental and total fatigue increased significantly as performance on the memory tests, following the divided attention condition, decreased, but only in the mTBI group. CONCLUSIONS: Results show lingering memory deficits, and suggest that cognitive tasks may be experienced as psychologically more demanding in those with a mTBI, even months or years after injury.

A case for using methods from natural science in advancing the field of cognitive neuroscience.

Cognitive neuroscience seeks to pinpoint the neural basis of cognitive function. Application of scientific methods can be credited for its advancement within the field of psychology. Past approaches such as phrenology, that linked bumps on the skull to mental capabilities, initially gained popularity, but the lack of experimental testing contributed to its demise. Research in neuropsychology and the use of the double dissociation experimental technique subsequently emerged. Objective measurements of behaviour following selective damage within the brain led to a paradigm shift. More recently, application of the subtraction technique, coupled with the emergence of cognitive neuroimaging tools, has allowed psychologists to isolate and measure specific functions such as language, vision, memory, and recognition of emotion. Importantly, these approaches enable reliable prediction of behaviours, given parameters of brain integrity, a key goal within the field of psychology.

Enhancing memory using enactment: does meaning matter in action production?

ABSTRACTEnactment is an encoding strategy in which performing an action related to a target item enhances memory for that word, relative to verbal encoding. Precisely how this motor activity aids recall is unclear. We examined whether the action created during encoding needed to be semantically relevant to the to-be-remembered word, to enhance memory. In Experiment 1, participants were asked to either (a) enact, (b) perform unrelated motoric gestures, or (c) read forty-five action verbs. On a subsequent free-recall test, memory for enacted words was significantly higher relative to words read, or encoded with unrelated gestures. In Experiment 2, to reduce the ambiguity associated with initiating an unrelated gesture, participants were instructed to write target words in the air. Results were similar to Experiment 1. In Experiment 3, we replicated the results of Experiment 2 using video conferencing to record the onset time of action initiation for enacted, unrelated gesture, and read trials. Results showed that planning of meaningful actions may also contribute to the memory performance as evidenced by a longer onset time to initiate an action on enactment relative to gesturing and reading trials. These findings suggest that planning and executing meaningful actions drive the enactment benefit.

Understanding autobiographical memory content using computational text analysis.

Although research on autobiographical memory (AM) continues to grow, there remain few methods to analyze AM content. Past approaches are typically manual, and prohibitively time- and labour-intensive. These methodological limitations are concerning because content may provide insights into the nature and functions of AM. In particular, analyzing content in recurrent involuntary autobiographical memories (IAMs; those that spring to mind unintentionally and repetitively) could resolve controversies about whether these memories typically involve mundane or distressing events. Here, we present computational methods that can analyze content in thousands of participants' AMs, without needing to hand-code each memory. A sample of 6,187 undergraduates completed surveys about recurrent IAMs, resulting in 3,624 text descriptions. Using frequency analyses, we identified common (e.g., "time", "friend") and distinctive words in recurrent IAMs (e.g., "argument" as distinctive to negative recurrent IAMs). Using structural topic modelling, we identified coherent topics (e.g., "Negative past relationships", "Conversations", "Experiences with family members") within recurrent IAMs and found that topic use significantly differed depending on the valence of these memories. Computational methods allowed us to analyze large quantities of AM content with enhanced granularity and reproducibility. We present the means to enable future research on AM content at an unprecedented scope and scale.

Machine learning to detect invalid text responses: Validation and comparison to existing detection methods.

A crucial step in analysing text data is the detection and removal of invalid texts (e.g., texts with meaningless or irrelevant content). To date, research topics that rely heavily on analysis of text data, such as autobiographical memory, have lacked methods of detecting invalid texts that are both effective and practical. Although researchers have suggested many data quality indicators that might identify invalid responses (e.g., response time, character/word count), few of these methods have been empirically validated with text responses. In the current study, we propose and implement a supervised machine learning approach that can mimic the accuracy of human coding, but without the need to hand-code entire text datasets. Our approach (a) trains, validates, and tests on a subset of texts manually labelled as valid or invalid, (b) calculates performance metrics to help select the best model, and (c) predicts whether unlabelled texts are valid or invalid based on the text alone. Model validation and evaluation using autobiographical memory texts indicated that machine learning accurately detected invalid texts with performance near human coding, significantly outperforming existing data quality indicators. Our openly available code and instructions enable new methods of improving data quality for researchers using text as data.

Divided attention at encoding or retrieval interferes with emotionally enhanced memory for words.

Emotional information is typically better remembered than neutral information. We asked whether emotional, compared to neutral, words were less vulnerable to the detrimental effects of divided attention. In two experiments, undergraduate students intentionally encoded words of intermixed valence (neutral, negative, or positive) and arousal (neutral, high, or low). Following a filled delay, memory was assessed with a free recall test. In Experiment 1, participants encoded visually-presented words under either full attention (FA; no distracting task) or divided attention (DA; concurrently making animacy decisions to auditorily-presented distractor words) in a counterbalanced, within-subjects design. As expected following FA at encoding, recall was significantly enhanced for negative compared to neutral words. Following DA at encoding, recall was significantly impaired across all valences. Critically, DA at encoding also eliminated the memory benefit for negative information: recall of negative words was no longer significantly different from neutral or positive words. In Experiment 2, we manipulated attention at retrieval rather than encoding. Remarkably, results from Experiment 1 were replicated: DA eliminated the well-known emotionality boost for negative words. In both experiments, memory for positive words did not significantly differ from neutral. Findings suggest that DA during either encoding or retrieval can interfere with the specific mechanisms by which negative emotion typically improves memory.

Recurrent involuntary autobiographical memories: characteristics and links to mental health status.

Memories of events from one's personal past that come to mind unintentionally and effortlessly are termed involuntary autobiographical memories (IAMs). Recurrent IAMs are known as relevant to many disorders within clinical literature. However, less is known about their links with mental health status in the general population. In the current study, 2184 undergraduate students completed surveys assessing occurrence of any recurrent IAMs. Participants also wrote a description of their most frequently recurring IAM and rated it on phenomenological characteristics, such as frequency, valence, vividness, and centrality. Results showed that the majority of our sample experienced recurrent IAMs, replicating previous findings, but most of these memories were emotionally negative, unlike past work. Importantly, negative recurrent IAMs were associated with significantly more mental health concerns, including symptoms of depression, anxiety, and posttraumatic stress. We also found that frequency of IAM recurrence was predicted by the memory's age, level of completeness/detail, emotional intensity, and centrality to one's life story. Further, descriptions of positive recurrent IAMs contained significantly more episodic detail compared to negative or neutral ones, suggesting that emotional regulation may play a role in how recurrent IAMs are recounted. Recurrent IAMs, and their characteristics, serve as a window into mental health status.

Drawing as an Encoding Tool: Memorial Benefits in Younger and Older Adults.

Background/Study Context. In a recent study, drawing pictures relative to writing words at encoding has been shown to benefit later memory performance in young adults. In the current study, we sought to test whether older adults' memory might also benefit from drawing as an encoding strategy. Our prediction was that drawing would serve as a particularly effective form of environmental support at encoding as it encourages a more detailed perceptual representation. METHODS: Participants were presented 30 nouns, one at a time, and asked to either draw a picture or repeatedly write out the word, which was followed by a free recall test for all words (Experiment 1). In Experiment 2, we added an elaborative processing task in which we asked participants to list physical characteristics of the objects. In Experiment 3, we probed recognition memory for the words. RESULTS: Of the words recalled in Experiment 1, a larger proportion had been drawn than written at encoding, and this effect was larger in older relative to younger adults. In Experiment 2, we demonstrated that drawing improves memory in both younger and older adults more than does an elaborative encoding task consisting of listing descriptive characteristics of the target nouns. In Experiment 3, older and younger adults drew or wrote out words at encoding, and subsequently provided Remember-Know-New recognition memory decisions. We showed that drawing reduced age-related differences in Remember responses. CONCLUSIONS: We suggest that incorporating visuo-perceptual information into the memory trace, by drawing pictures at study, increases reliance of the memory trace on visual sensory regions, which are relatively intact in normal aging, relative to simply writing out or elaborately encoding words. Overall, results indicate that drawing is a highly valuable form of environmental support that can significantly enhance memory performance in older adults.

Autobiographical and episodic memory deficits in mild traumatic brain injury.

Those who have suffered a concussion, otherwise known as a mild traumatic brain injury (mTBI), often complain of lingering memory problems. However, there is little evidence in the behavioral literature reliably demonstrating memory deficits. Thus, in the present study, cognitive profiles including measures of general executive functioning and processing speed, as well as episodic and semantic memory were collected in younger and older adult participants with or without a remote (>1year prior to testing) mTBI. We first investigated whether there were observable episodic and autobiographical memory impairments associated with mTBI within an otherwise healthy young group. Next, because previous work had demonstrated some overlap in patterns of behavioral impairment in normally aging adults and younger adults with a history of mTBI (e.g. Ozen, Fernandes, Clark, & Roy, 2015), we sought to determine whether these groups displayed similar cognitive profiles. Lastly, we conducted an exploratory analysis to test whether having suffered an mTBI might exacerbate age-related cognitive decline. Results showed the expected age-related decline in episodic memory performance, coupled with a relative preservation of semantic memory in older adults. Importantly, this pattern was also present in younger adults with a history of remote mTBI. No differences were observed across older adult groups based on mTBI status. Logistic regression analyses, using each measure in our battery as a predictor, successfully classified mTBI status in younger participants with a high degree of specificity (79.5%). These results indicate that those who have had an mTBI demonstrate a distinct cognitive signature, characterized by impairment in episodic and autobiographical memory, coupled with a relative preservation of semantic memory.

The role of semantically related distractors during encoding and retrieval of words in long-term memory.

We examined the influence of divided attention (DA) on recognition of words when the concurrent task was semantically related or unrelated to the to-be-recognised target words. Participants were asked to either study or retrieve a target list of semantically related words while simultaneously making semantic decisions (i.e., size judgements) to another set of related or unrelated words heard concurrently. We manipulated semantic relatedness of distractor to target words, and whether DA occurred during the encoding or retrieval phase of memory. Recognition accuracy was significantly diminished relative to full attention, following DA conditions at encoding, regardless of relatedness of distractors to study words. However, response times (RTs) were slower with related compared to unrelated distractors. Similarly, under DA at retrieval, recognition RTs were slower when distractors were semantically related than unrelated to target words. Unlike the effect from DA at encoding, recognition accuracy was worse under DA at retrieval when the distractors were related compared to unrelated to the target words. Results suggest that availability of general attentional resources is critical for successful encoding, whereas successful retrieval is particularly reliant on access to a semantic code, making it sensitive to related distractors under DA conditions.

Interfering with memory for faces: The cost of doing two things at once.

We inferred the processes critical for episodic retrieval of faces by measuring susceptibility to memory interference from different distracting tasks. Experiment 1 examined recognition of studied faces under full attention (FA) or each of two divided attention (DA) conditions requiring concurrent decisions to auditorily presented letters. Memory was disrupted in both DA relative to FA conditions, a result contrary to a material-specific account of interference effects. Experiment 2 investigated whether the magnitude of interference depended on competition between concurrent tasks for common processing resources. Studied faces were presented either upright (configurally processed) or inverted (featurally processed). Recognition was completed under FA, or DA with one of two face-based distracting tasks requiring either featural or configural processing. We found an interaction: memory for upright faces was lower under DA when the distracting task required configural than featural processing, while the reverse was true for memory of inverted faces. Across experiments, the magnitude of memory interference was similar (a 19% or 20% decline from FA) regardless of whether the materials in the distracting task overlapped with the to-be-remembered information. Importantly, interference was significantly larger (42%) when the processing demands of the distracting and target retrieval task overlapped, suggesting a processing-specific account of memory interference.

Age differences in effectiveness of encoding techniques on memory.

We compared the effectiveness of different encoding techniques across the adult age range. Three hundred participants: 100 younger, 100 middle-aged, and 100 older adults, were asked to encode a set of visually presented concrete and abstract words. Participants were shown target words one at a time, along with prompts (randomly and intermixed, within-subject) to either silently read, read aloud, write, or draw a picture of the target, for a duration of 10-seconds each. On a later free recall test, participants were given 2-minutes to type all the words they could remember from the encoding phase. Across age groups, we showed that drawing, writing, and reading aloud as encoding techniques yielded better memory than silently reading words, with drawing leading to the largest boost. While memory performance did decrease as age increased, it interacted with the encoding technique. Of note, there were no differences in memory performance in middle-aged compared to young adults. Importantly, age differences in memory emerged only when drawing was used as the encoding strategy, in line with previously reported age-related deficits in generating imagery, or integrating it with motoric processes. Despite this, concrete relative to abstract words that were drawn or written during encoding were better retained, regardless of age, suggesting these techniques facilitate formation of age-invariant visuo-spatial representations. Our findings suggest that whether age differences in memory emerge depends on the strategy used at encoding, and the type of information being encoded.

Which Encoding Techniques Facilitate Comprehension?

Previous work suggests that similar cognitive processes contribute to memory and comprehension. This is unsurprising as both begin with a common process: encoding. Despite this, the investigation of techniques that benefit memory and comprehension has proceeded separately. In the current study, we compared the robust memory techniques of production and drawing to a similarly effective comprehension strategy known as paraphrasing. Depending on the group, participants were asked to either engage in one of the encoding types (read aloud, draw, or paraphrase) or to silently read 20 term-definition pairs (randomly intermixed and counterbalanced). The encoding techniques of drawing and paraphrasing resulted in better performance on a multiple-choice test of concept comprehension, relative to silently reading. By contrast, reading aloud at encoding did not lead to any benefit relative to silently reading. The results suggest that techniques that invoke transformation of the to-be-remembered text into another format, be it into a picture (drawing) or personally relevant summary (paraphrasing), are particularly effective at improving comprehension. By contrast, encoding techniques that mainly provide a perceptual repetition (production and silent reading) are less effective.

Disentangling boredom from depression using the phenomenology and content of involuntary autobiographical memories.

Recurrent involuntary autobiographical memories (IAMs) are memories retrieved unintentionally and repetitively. We examined whether the phenomenology and content of recurrent IAMs could differentiate boredom and depression, both of which are characterized by affective dysregulation and spontaneous thought. Participants (n = 2484) described their most frequent IAM and rated its phenomenological properties (e.g., valence). Structural topic modeling, a method of unsupervised machine learning, identified coherent content within the described memories. Boredom proneness was positively correlated with depressive symptoms, and both boredom proneness and depressive symptoms were correlated with more negative recurrent IAMs. Boredom proneness predicted less vivid recurrent IAMs, whereas depressive symptoms predicted more vivid, negative, and emotionally intense ones. Memory content also diverged: topics such as relationship conflicts were positively predicted by depressive symptoms, but negatively predicted by boredom proneness. Phenomenology and content in recurrent IAMs can effectively disambiguate boredom proneness from depressive symptoms in a large sample of undergraduate students from a racially diverse university.

Long-term working memory deficits after concussion: electrophysiological evidence.

BACKGROUND: Persistent complaints of lingering memory and concentration difficulties are common following a concussion, although the brain basis of these is unknown. Some suggest abnormalities can be found on the P300 event-related potential component, recorded using electroencephalography (EEG), despite unobservable cognitive impairments. OBJECTIVE: To examine the P300 and cognitive performance following a remote concussion during an n-back task that varies in working memory load. RESEARCH DESIGN: Seventeen participants with a remote concussion and 17 controls performed a visual n-back task in which working memory demands were systematically increased by manipulating cognitive load. Participants also completed neuropsychological and self-report measures. RESULTS: The concussion group showed a decrease in P300 amplitude compared to controls that was independent of working memory load on the n-back task. While no performance differences were observed between groups, P300 amplitude was negatively correlated with response times at higher loads in both groups. CONCLUSION: High functioning young adults with a remote concussion may have inefficient recruitment of processing resources for target identification, evident by the attenuated P300. The negative correlations between response time and P300 amplitude suggest that the time necessary to accurately respond to targets increases as the efficiency of allocating processing resources decreases during highly demanding working memory tasks.

A positivity effect in older adults' memorability judgments of pictures.

UNLABELLED: BACKGROUND/STUDY CONTEXT: A growing literature suggests that older adults are biased to preferentially cognitively process positively valenced information. The authors investigated whether this bias extended to preferential selection of information to remember, and also examined whether the arousal invoked by stimuli biased item selection and memory. METHODS: Thirty older (63-88 years of age) and 30 younger (18-25 years of age) adults viewed emotional (positive, negative) and neutral pictures that varied in arousal (low, high), and were asked to select a subset they deemed memorable (memorability judgments), before recalling pictures. Repeated-measures analyses of variance were conducted to examine aging-related differences in selection and recall of positive, negative, and neutral pictures, and of low- and high-arousal pictures. RESULTS: Older adults selected more positive pictures as memorable, whereas in younger adults selection did not differ by valence. In both age groups, recall of positive pictures was highest. Older adults selected more low- than high-arousal pictures as memorable, although recall was greater for high- than low-arousal pictures in both age groups. CONCLUSION: Findings are consistent with the view that the aging-related positivity bias is under cognitive control, and suggest an awareness of this in older adults. Future investigations should seek to disentangle the influence of positive valence from other factors (e.g., perceptual, semantic, arousal level) on older adults' memorability judgments.