Using a flashlight-contingent window paradigm to investigate visual search and object memory in virtual reality and on computer screens.

A popular technique to modulate visual input during search is to use gaze-contingent windows. However, these are often rather discomforting, providing the impression of visual impairment. To counteract this, we asked participants in this study to search through illuminated as well as dark three-dimensional scenes using a more naturalistic flashlight with which they could illuminate the rooms. In a surprise incidental memory task, we tested the identities and locations of objects encountered during search. Importantly, we tested this study design in both immersive virtual reality (VR; Experiment 1) and on a desktop-computer screen (Experiment 2). As hypothesized, searching with a flashlight increased search difficulty and memory usage during search. We found a memory benefit for identities of distractors in the flashlight condition in VR but not in the computer screen experiment. Surprisingly, location memory was comparable across search conditions despite the enormous difference in visual input. Subtle differences across experiments only appeared in VR after accounting for previous recognition performance, hinting at a benefit of flashlight search in VR. Our findings highlight that removing visual information does not necessarily impair location memory, and that screen experiments using virtual environments can elicit the same major effects as VR setups.

Interacción del tratamiento y el control de la presión en el deterioro de la memoria incidental visuoespacial en pacientes con hipertensión arterial sistémica / Pressure control and treatment interact in the deterioration of incidental visuospatial memory in hypertensive patients

Resumen Antecedentes: La hipertensión arterial sistémica (HAS) es el principal factor de riesgo para el deterioro cognitivo; por otro lado, la memoria visuoespacial es más vulnerable al envejecimiento. Algunos fármacos antihipertensivos tienen un efecto neuroprotector, pero tal efecto puede enmascararse o bien no manifestarse por comorbilidad o por falta de control efectivo de la presión arterial. Objetivo: Evaluar las alteraciones en la memoria visuoespacial incidental de pacientes con HAS en relación con su tratamiento antihipertensivo y su control de la presión. Método: Se incluyeron 80 pacientes con HAS (46 mujeres), agrupados por su medicación en bloqueadores de los receptores de la angiotensina II (BRA) o inhibidores de la enzima convertidora de angiotensina (IECA). Se realizó un análisis de correlaciones múltiples para los puntajes obtenidos en la prueba de memoria visuoespacial incidental/intencional y un análisis de modelos mixtos (factores fijos: tratamiento, control de la presión y comorbilidad con diabetes; factores aleatorios: edad, escolaridad, meses desde el diagnóstico de HAS y coeficiente intelectual). Resultados: De los pacientes controlados, la mayoría de los que recibían BRA fueron eficientes y los que recibían IECA fueron deficientes. De los que recibían IECA, los descontrolados hipertensos fueron más eficientes que los normotensos. La memoria visuoespacial se correlacionó negativamente con la presión sistólica a pesar de no haber diferencias en MoCA y Raven. Conclusiones: La eficiencia en la memoria visuoespacial dependió de la interacción del tratamiento y el control de la presión. Ambos factores, tratamiento y control efectivo de la presión, deben considerarse en la evaluación del deterioro cognitivo asociado a la HAS.

Abstract Background: Systemic hypertension (SH) is the main risk factor to cognitive deterioration, whereas visuospatial memory is more vulnerable to ageing. Some antihypertensive agents have a neuroprotector effect, however, such effects could be masked by comorbidities and/or the lack of effective control on the arterial pressure of patients. Objective: To assess this, the evaluation of incidental visuospatial memory of SH patients and the relation to the treatment received and the effective control of pressure were made. Method: 80 patients (46 woman) were included grouped by the received medication: angiotensin 2 receptor blockers (ARB) or angiotensin converting enzyme inhibitors (ACEI). A multiple correlation analysis between visuospatial scores and clinical variables was made; also, a mixed model analysis (fixed factors: treatment, pressure control, diabetes comorbidity; aleatory factors: age, schooling, months from SH diagnoses). Results: Half of the patients had a controlled pressure, from them the higher proportion received ARB, and a minor number of patients received ACEI. The normotensive patients receiving ACEI were inefficient whereas the hypertensive patients were more efficient. The systolic pressure was negatively related with the visuospatial scores in spite of no correlations occurred with MoCA and Raven tests. Conclusions: The visuospatial incidental/intentional scores were negatively correlated with systolic pressure. The efficiency in the visuospatial ability depends on the interaction of treatment and effective control of blood pressure. The interaction between treatment and effective pressure control must be taken in count when cognitive deterioration is studied.

Pressure control and treatment interact in the deterioration of incidental visuospatial memory in hypertensive patients.

BACKGROUND: Systemic hypertension (SH) is the main risk factor to cognitive deterioration, whereas visuospatial memory is more vulnerable to ageing. Some antihypertensive agents have a neuroprotector effect, however, such effects could be masked by comorbidities and/or the lack of effective control on the arterial pressure of patients. OBJECTIVE: To assess this, the evaluation of incidental visuospatial memory of SH patients and the relation to the treatment received and the effective control of pressure were made. METHOD: 80 patients (46 woman) were included grouped by the received medication: angiotensin 2 receptor blockers (ARB) or angiotensin converting enzyme inhibitors (ACEI). A multiple correlation analysis between visuospatial scores and clinical variables was made; also, a mixed model analysis (fixed factors: treatment, pressure control, diabetes comorbidity; aleatory factors: age, schooling, months from SH diagnoses). RESULTS: Half of the patients had a controlled pressure, from them the higher proportion received ARB, and a minor number of patients received ACEI. The normotensive patients receiving ACEI were inefficient whereas the hypertensive patients were more efficient. The systolic pressure was negatively related with the visuospatial scores in spite of no correlations occurred with MoCA and Raven tests. CONCLUSIONS: The visuospatial incidental/intentional scores were negatively correlated with systolic pressure. The efficiency in the visuospatial ability depends on the interaction of treatment and effective control of blood pressure. The interaction between treatment and effective pressure control must be taken in count when cognitive deterioration is studied.

ANTECEDENTES: La hipertensión arterial sistémica (HAS) es el principal factor de riesgo para el deterioro cognitivo; por otro lado, la memoria visuoespacial es más vulnerable al envejecimiento. Algunos fármacos antihipertensivos tienen un efecto neuroprotector, pero tal efecto puede enmascararse o bien no manifestarse por comorbilidad o por falta de control efectivo de la presión arterial. OBJETIVO: Evaluar las alteraciones en la memoria visuoespacial incidental de pacientes con HAS en relación con su tratamiento antihipertensivo y su control de la presión. MÉTODO: Se incluyeron 80 pacientes con HAS (46 mujeres), agrupados por su medicación en bloqueadores de los receptores de la angiotensina II (BRA) o inhibidores de la enzima convertidora de angiotensina (IECA). Se realizó un análisis de correlaciones múltiples para los puntajes obtenidos en la prueba de memoria visuoespacial incidental/intencional y un análisis de modelos mixtos (factores fijos: tratamiento, control de la presión y comorbilidad con diabetes; factores aleatorios: edad, escolaridad, meses desde el diagnóstico de HAS y coeficiente intelectual). RESULTADOS: De los pacientes controlados, la mayoría de los que recibían BRA fueron eficientes y los que recibían IECA fueron deficientes. De los que recibían IECA, los descontrolados hipertensos fueron más eficientes que los normotensos. La memoria visuoespacial se correlacionó negativamente con la presión sistólica a pesar de no haber diferencias en MoCA y Raven. CONCLUSIONES: La eficiencia en la memoria visuoespacial dependió de la interacción del tratamiento y el control de la presión. Ambos factores, tratamiento y control efectivo de la presión, deben considerarse en la evaluación del deterioro cognitivo asociado a la HAS.

How does searching for faces among similar-looking distractors affect distractor memory?

Prior research has shown that searching for multiple targets in a visual search task enhances distractor memory in a subsequent recognition test. Three non-mutually exclusive accounts have been offered to explain this phenomenon. The mental comparison hypothesis states that searching for multiple targets requires participants to make more mental comparisons between the targets and the distractors, which enhances distractor memory. The attention allocation hypothesis states that participants allocate more attention to distractors because a multiple-target search cue leads them to expect a more difficult search. Finally, the partial match hypothesis states that searching for multiple targets increases the amount of featural overlap between targets and distractors, which necessitates greater attention in order to reject each distractor. In two experiments, we examined these hypotheses by manipulating visual working memory (VWM) load and target-distractor similarity of AI-generated faces in a visual search (i.e., RSVP) task. Distractor similarity was manipulated using a multidimensional scaling model constructed from facial landmarks and other metadata of each face. In both experiments, distractors from multiple-target searches were recognized better than distractors from single-target searches. Experiment 2 additionally revealed that increased target-distractor similarity during search improved distractor recognition memory, consistent with the partial match hypothesis.

In search for a neuropsychological marker of ADHD: findings from incidental memory testing.

This paper reports on a study where the incidental memory of 18 children with ADHD and 18 typically developing peers was assessed by means of a conventional two-phase recognition memory test. In the study phase participants were required to categorize as a living or non-living a set of 64 stimuli from 8 semantic categories. In the test phase, they were required to recognize "target" (i.e., stimuli from the first set) from "non-target" stimuli. Children with ADHD were overall less accurate and much slower than TD controls in identifying both living and non-living items. Moreover, while most of TD participants made very few, if any, errors, only 7 out of 18 participants with ADHD scored near ceiling, and 2 of them scored below chance level. Following the Signal Detection Theory approach, the participants' performance on the test phase was scored in terms of d prime (d') values. Children with ADHD had lower d' indexes compared to controls both for living and non-living stimuli, although this difference did not reach statistical significance. More interestingly, the variability of the d' values was higher in the ADHD compared to Controls. Taken together, findings from this study indicate that at least some of the children with ADHD have a genuine impairment in processing visual stimuli. More generally, these results cast doubts on the idea that ADHD represents a stable nosographic entity.

Aging-related episodic-like memory decline in dogs.

Episodic memory, in humans, is the memory most affected by age-related deterioration or the constitution of neurodegenerative pathologies, such as Alzheimer's disease. However, it is unknown whether this relationship is also present in nonhuman animals. Since studies in birds, rats, primates, and dogs have been shown to have episodic-like memory, more studies aiming to improve the present understanding of this relationship in nonhuman animals are important to aid the development of new translational models for neurodegenerative disorders. Knowing that dogs (Canis familiaris) represent a promising experimental model for neurodegenerative disorders, a memory retrieval test was conducted with 90 clinically healthy domestic dogs of different ages, both sexes, and distinct breeds, for the purpose of evaluating episodic-like memory. The present study adapted a test that corroborates episodic memory requirements through incidental codification of experienced events. We performed a test with two exposure phases, with different characteristics between them, so that in the third phase it was necessary to integrate previous experiences in order to achieve success in the test. In our study, it was possible to verify the decline of episodic memory in elderly dogs, even clinically healthy, regardless of the dogs' sex and size. This episodic-like memory decline observed in elderly dogs may be related to the physiological process of aging or preclinical pathological manifestation of cognitive impairment, similar as reported in humans. More studies should be carried out evaluating episodic-like memory in dogs with suspected of canine cognitive dysfunction syndrome in order to better understand the physiological and pathological behavior of this type of memory in canine species.

Flipping the world upside down: Using eye tracking in virtual reality to study visual search in inverted scenes.

Image inversion is a powerful tool for investigating cognitive mechanisms of visual perception. However, studies have mainly used inversion in paradigms presented on twodimensional computer screens. It remains open whether disruptive effects of inversion also hold true in more naturalistic scenarios. In our study, we used scene inversion in virtual reality in combination with eye tracking to investigate the mechanisms of repeated visual search through three-dimensional immersive indoor scenes. Scene inversion affected all gaze and head measures except fixation durations and saccade amplitudes. Our behavioral results, surprisingly, did not entirely follow as hypothesized: While search efficiency dropped significantly in inverted scenes, participants did not utilize more memory as measured by search time slopes. This indicates that despite the disruption, participants did not try to compensate the increased difficulty by using more memory. Our study highlights the importance of investigating classical experimental paradigms in more naturalistic scenarios to advance research on daily human behavior.

Get Your Guidance Going: Investigating the Activation of Spatial Priors for Efficient Search in Virtual Reality.

Repeated search studies are a hallmark in the investigation of the interplay between memory and attention. Due to a usually employed averaging, a substantial decrease in response times occurring between the first and second search through the same search environment is rarely discussed. This search initiation effect is often the most dramatic decrease in search times in a series of sequential searches. The nature of this initial lack of search efficiency has thus far remained unexplored. We tested the hypothesis that the activation of spatial priors leads to this search efficiency profile. Before searching repeatedly through scenes in VR, participants either (1) previewed the scene, (2) saw an interrupted preview, or (3) started searching immediately. The search initiation effect was present in the latter condition but in neither of the preview conditions. Eye movement metrics revealed that the locus of this effect lies in search guidance instead of search initiation or decision time, and was beyond effects of object learning or incidental memory. Our study suggests that upon visual processing of an environment, a process of activating spatial priors to enable orientation is initiated, which takes a toll on search time at first, but once activated it can be used to guide subsequent searches.

The detail is in the difficulty: Challenging search facilitates rich incidental object encoding.

When searching for objects in the environment, observers necessarily encounter other, nontarget, objects. Despite their irrelevance for search, observers often incidentally encode the details of these objects, an effect that is exaggerated as the search task becomes more challenging. Although it is well established that searchers create incidental memories for targets, less is known about the fidelity with which nontargets are remembered. Do observers store richly detailed representations of nontargets, or are these memories characterized by gist-level detail, containing only the information necessary to reject the item as a nontarget? We addressed this question across two experiments in which observers completed multiple-target (one to four potential targets) searches, followed by surprise alternative forced-choice (AFC) recognition tests for all encountered objects. To assess the detail of incidentally stored memories, we used similarity rankings derived from multidimensional scaling to manipulate the perceptual similarity across objects in 4-AFC (Experiment 1a) and 16-AFC (Experiments 1b and 2) tests. Replicating prior work, observers recognized more nontarget objects encountered during challenging, relative to easier, searches. More importantly, AFC results revealed that observers stored more than gist-level detail: When search objects were not recognized, observers systematically chose lures with higher perceptual similarity, reflecting partial encoding of the search object's perceptual features. Further, similarity effects increased with search difficulty, revealing that incidental memories for visual search objects are sharpened when the search task requires greater attentional processing.

Inattentional blindness and information relevance of variable message signs.

It has been suggested that Variable Message Signs (VMS) become less effective at communicating important traffic information when irrelevant information is also displayed on them. The purpose of this study was to examine if practice reading irrelevant information on a VMS influenced compliance with, and memory for a detour message. Thirty-nine participants were randomly assigned to one of three groups who drove a simulated road; one receiving only a detour message on the VMS, one group received irrelevant VMS messages before the detour message, and a third group received the same messages but the detour message was inconsistent with their destination. Of interest were both the participants' compliance with the target detour message, as well as their later recall and recognition of the message. The results suggested that, first and foremost, there was significantly lower compliance with the detour message when it had been preceded by irrelevant messages on the VMS. All of the groups showed reasonably good memory for the detour message. The implications of the present study are that presentation of irrelevant messages, including advertisements and safety slogans, may result in reduced compliance to traffic-relevant messages on VMSs.

Search superiority: Goal-directed attentional allocation creates more reliable incidental identity and location memory than explicit encoding in naturalistic virtual environments.

We use representations and expectations formed during life-long learning to support attentional allocation and perception. In comparison to traditional laboratory investigations, real-world memory formation is usually achieved without explicit instruction and on-the-fly as a by-product of natural interactions with our environment. Understanding this process and the quality of naturally formed representations is critical to understanding how memory is used to guide attention and perception. Utilizing immersive, navigable, and realistic virtual environments, we investigated incidentally generated memory representations by comparing them to memories for items which were explicitly memorized. Participants either searched for objects embedded in realistic indoor environments or explicitly memorized them for follow-up identity and location memory tests. We show for the first time that memory for the identity of naturalistic objects and their location in 3D space is higher after incidental encoding compared to explicit memorization, even though the subsequent memory tests came as a surprise to participants. Relating gaze behavior to memory performance revealed that encoding time was more predictive of subsequent memory when participants explicitly memorized an item, compared to incidentally encoding it. Our results suggest that the active nature of guiding attentional allocation during proactive behavior allows for behaviorally optimal formation and utilization of representations. This highlights the importance of investigating cognition under ecologically valid conditions and shows that understanding the most natural processes for encoding and maintaining information is critical for understanding adaptive behavior.

Incidental image memorability.

Recent studies using intentional memory tasks showed that images differ consistently in memorability. Here, we used a surprise recognition memory test. We asked how incidental encoding would affect the consistency and ranking of the memorability scores. If memorability is truly an intrinsic property of the image, one should not expect large differences between incidental and intentional conditions. On the other hand, participants might process images differently when not anticipating a memory test, yielding different results. The study list of our incidental memory task was identical to our previous, intentional study. Participants were to watch the images of this list carefully as they appeared on the screen one by one (free viewing); supposedly for a study about eye movements. Afterwards, a surprise recognition memory test was administered. Despite the free viewing instructions during the study phase, the resulting incidental image memorability scores still showed high levels of consistency across participants. In addition, the overlap between the incidental and intentional memorability ranking was large. These results provide further support for the idea of memorability as an intrinsic image property and add to its ecological validity, as people rarely memorise images intentionally.

The effect of working memory maintenance on long-term memory.

Initially inspired by the Atkinson and Shiffrin model, researchers have spent a half century investigating whether actively maintaining an item in working memory (WM) leads to improved subsequent long-term memory (LTM). Empirical results have been inconsistent, and thus the answer to the question remains unclear. We present evidence from 13 new experiments as well as a meta-analysis of 61 published experiments. Both the new experiments and meta-analysis show clear evidence that increased WM maintenance of a stimulus leads to superior recognition for that stimulus in subsequent LTM tests. This effect appears robust across a variety of experimental design parameters, suggesting that the variability in prior results in the literature is probably due to low power and random chance. The results support theories on which there is a close link between WM and LTM mechanisms, while challenging claims that this relationship is specific to verbal memory and evolved to support language acquisition.

Emotional valence may influence memory performance for visual artworks in Parkinson's disease.

BACKGROUND: Non-motor symptoms in Parkinson's disease (PD) include reduced reactivity to emotional stimuli. Visual artworks can evoke emotional responses. Motor, sensorial and cognitive networks implicated in the aesthetic experience and in the emotional-reward domain show a significant overlap with the pathological nigrostriatal, mesocortical and mesolimbic circuitry that characterises PD. METHODS: Memory enhancement by emotional stimuli such as visual artwork-stimuli was explored in 12 right-sided and 12 left-sided non-demented-PD patients, 12 Alzheimer's disease patients (AD) and 13 healthy controls (HC). Ten emotional and 10 non-emotional stimuli were previously identified based on the ratings of the emotional impact provided by 45 non-PD subjects on 82 pictures of paintings. Only figurative artworks were included. Patients and HC were requested to rate on a 7-point scale the emotional impact of 20 pictures; they were then requested to recognise the 20 pictures amongst 20 distractors (incidental memory task). RESULTS AND CONCLUSION: Recognition of emotional stimuli was more accurate compared to non-emotional stimuli in AD, left-sided PD and HC; right-sided PD did not show sensitivity to the emotional valence of the stimuli suggesting the involvement of the nigrostriatal, mesocortical and mesolimbic circuitry of the left hemisphere in the emotional-reward system related to the aesthetic experience.

Incidental memory for colour word associates processed in colour naming and reading aloud tasks: is a blue ocean more memorable than a yellow one?

Congruency effects for colour word associates (e.g., ocean) have been reported in Stroop colour naming tasks. However, incidental memory for such words after word reading and colour naming tasks has not been examined. In the current study, participants incidentally recalled colour word associates (e.g., ocean) and neutral words (e.g., lawyer) immediately after naming their font colour (Experiment 1a) or reading them aloud (Experiment 1b). In both tasks, recall was better for congruent colour word associates (e.g., ocean appearing in blue) than incongruent colour word associates (e.g., ocean appearing in green) or neutral items (lawyer appearing in blue). This outcome is consistent with the idea that co-activation of a semantic colour code and a lexical representation strengthens the episodic memory representation and makes it more accessible.

Capturing real-life forgetting in transient epileptic amnesia via an incidental memory test.

Transient epileptic amnesia (TEA) is an epileptic syndrome characterized by recurrent, brief episodes of amnesia. Patients with TEA often complain of interictal (between attacks) retention deficits, characterised by an 'evaporation' of memories for recent events over days to weeks. Clinical tests of anterograde memory often fail to corroborate these complaints as TEA patients commonly perform within the normal range after the standard 10-30-min delay period. Modified laboratory tests that include a 1-3 week delay period frequently reveal clear evidence of 'accelerated long-term forgetting' (ALF). However, they are not used routinely and lack ecological validity. In the present study we examined whether 'real-life' ALF can be captured via a controlled incidental memory test in TEA patients. To this end, the experimenter told 27 TEA patients and 32 controls a well-rehearsed amusing story, apparently as a way of making light conversation before starting a set of research experiments. Without prior warning, the experimenter subsequently probed the participants' memory of this story via tests of free recall and forced choice recognition after 30 min or 1 week. After 30 min retention was comparable in TEA patients and controls. After 1 week TEA patients retained significantly less story material than controls, and significant ALF was revealed in the TEA patients in the recognition test. Our data show that ALF in a 'real-life' situation can occur even when standard memory tests indicate normal memory function. Moreover, our data suggest that incidental memory tests can capture real-life ALF, and that forced-choice recognition tests might be more sensitive than free recall tests for the detection of real-life ALF.

The lower bounds of massive memory: Investigating memory for object details after incidental encoding.

Visual long-term memory capacity appears massive and detailed when probed explicitly. In the real world, however, memories are usually built from chance encounters. Therefore, we investigated the capacity and detail of incidental memory in a novel encoding task, instructing participants to detect visually distorted objects among intact objects. In a subsequent surprise recognition memory test, lures of a novel category, another exemplar, the same object in a different state, or exactly the same object were presented. Lure recognition performance was above chance, suggesting that incidental encoding resulted in reliable memory formation. Critically, performance for state lures was worse than for exemplars, which was driven by a greater similarity of state as opposed to exemplar foils to the original objects. Our results indicate that incidentally generated visual long-term memory representations of isolated objects are more limited in detail than recently suggested.

Exploring the Profile of Incidental Memory in Patients with Amnestic Mild Cognitive Impairment and Mild Alzheimer's Disease.

Incidental memory can be defined as the ability to acquire information unintentionally. The present study investigated incidental memory performance in amnestic mild cognitive impairment (aMCI) and mild Alzheimer's disease (AD) patients; additionally, hippocampal atrophy between groupswas examined. Twenty-nine aMCI patients (14 with hippocampal atrophy, measured by the Medial Temporal Lobe Atrophy scale), 15 mild AD patients, and 20 cognitively intact individuals underwent a detailed medical and neuropsychological assessment examining intentional memory, using the Hopkins Verbal Learning Test-Revised and the Brief Visuospatial Memory Test. Participants first took part in a driving simulator experiment, followed by an unexpected incidental memory questionnaire referring to elements related to the driving simulation. The mild AD group performed worse than the aMCI group and the control group both in incidental and intentional memory tasks, whereas the aMCI group differed significantly from the control group only in the intentional memory tasks. The incidental recognition memory task was the only measure that differed between aMCI patients with and without hippocampal atrophy. Moreover, incidental memory tasks were the only measures that correlated significantly with both left and right hippocampal atrophy. The current findings indicate that incidental memory testing may provide potentially useful information for detecting aMCI patients with greater hippocampal atrophy, who may be considered at higher risk of developing dementia due to AD.

Post-error Brain Activity Correlates With Incidental Memory for Negative Words.

The present study had three main objectives. First, we aimed to evaluate whether short-duration affective states induced by negative and positive words can lead to increased error-monitoring activity relative to a neutral task condition. Second, we intended to determine whether such an enhancement is limited to words of specific valence or is a general response to arousing material. Third, we wanted to assess whether post-error brain activity is associated with incidental memory for negative and/or positive words. Participants performed an emotional stop-signal task that required response inhibition to negative, positive or neutral nouns while EEG was recorded. Immediately after the completion of the task, they were instructed to recall as many of the presented words as they could in an unexpected free recall test. We observed significantly greater brain activity in the error-positivity (Pe) time window in both negative and positive trials. The error-related negativity amplitudes were comparable in both the neutral and emotional arousing trials, regardless of their valence. Regarding behavior, increased processing of emotional words was reflected in better incidental recall. Importantly, the memory performance for negative words was positively correlated with the Pe amplitude, particularly in the negative condition. The source localization analysis revealed that the subsequent memory recall for negative words was associated with widespread bilateral brain activity in the dorsal anterior cingulate cortex and in the medial frontal gyrus, which was registered in the Pe time window during negative trials. The present study has several important conclusions. First, it indicates that the emotional enhancement of error monitoring, as reflected by the Pe amplitude, may be induced by stimuli with symbolic, ontogenetically learned emotional significance. Second, it indicates that the emotion-related enhancement of the Pe occurs across both negative and positive conditions, thus it is preferentially driven by the arousal content of an affective stimuli. Third, our findings suggest that enhanced error monitoring and facilitated recall of negative words may both reflect responsivity to negative events. More speculatively, they can also indicate that post-error activity of the medial prefrontal cortex may selectively support encoding for negative stimuli and contribute to their privileged access to memory.

Cingulo-opercular activity affects incidental memory encoding for speech in noise.

Correctly understood speech in difficult listening conditions is often difficult to remember. A long-standing hypothesis for this observation is that the engagement of cognitive resources to aid speech understanding can limit resources available for memory encoding. This hypothesis is consistent with evidence that speech presented in difficult conditions typically elicits greater activity throughout cingulo-opercular regions of frontal cortex that are proposed to optimize task performance through adaptive control of behavior and tonic attention. However, successful memory encoding of items for delayed recognition memory tasks is consistently associated with increased cingulo-opercular activity when perceptual difficulty is minimized. The current study used a delayed recognition memory task to test competing predictions that memory encoding for words is enhanced or limited by the engagement of cingulo-opercular activity during challenging listening conditions. An fMRI experiment was conducted with twenty healthy adult participants who performed a word identification in noise task that was immediately followed by a delayed recognition memory task. Consistent with previous findings, word identification trials in the poorer signal-to-noise ratio condition were associated with increased cingulo-opercular activity and poorer recognition memory scores on average. However, cingulo-opercular activity decreased for correctly identified words in noise that were not recognized in the delayed memory test. These results suggest that memory encoding in difficult listening conditions is poorer when elevated cingulo-opercular activity is not sustained. Although increased attention to speech when presented in difficult conditions may detract from more active forms of memory maintenance (e.g., sub-vocal rehearsal), we conclude that task performance monitoring and/or elevated tonic attention supports incidental memory encoding in challenging listening conditions.