Positive and negative effects of collaboration on suggestibility and false memory in online groups.

Previous studies demonstrated the positive and negative effects of collaboration on memory (both veridical and false recall) and suggestibility in face-to-face contexts. However, it remains unclear whether the same results can be observed in a virtual context. To clarify this issue, the present study examined the performance of 10 nominal triads and 10 collaborative triads in a fully online setting. Participants interacted live, in videoconference and were tested with the Gudjonsson Suggestibility Scale (GSS) and the Deese/Roediger-McDermott (DRM) task. For the GSS, the results replicated the in-person pattern of results, with collaborative triads showing the standard inhibition effect in the immediate and delayed (after 24 h) recall tasks; in addition, collaborative triads were less suggestible than nominal triads. For the DRM, we likewise found that collaboration decreased the recall and recognition of both studied items (the standard inhibitory effect) and critical lures (the error-pruning effect). We therefore conclude that remembering in a virtual context exhibits the same general properties as its in-person counterpart, at least when using a videoconference setting.

Deconstructing Reorienting of Attention: Cue Predictiveness Modulates the Inhibition of the No-target Side and the Hemispheric Distribution of the P1 Response to Invalid Targets.

Orienting of attention produces a "sensory gain" in the processing of visual targets at attended locations and an increase in the amplitude of target-related P1 and N1 ERPs. P1 marks gain reduction at unattended locations; N1 marks gain enhancement at attended ones. Lateral targets that are preceded by valid cues also evoke a larger P1 over the hemisphere contralateral to the no-target side, which reflects inhibition of this side of space [Slagter, H. A., Prinssen, S., Reteig, L. C., & Mazaheri, A. Facilitation and inhibition in attention: Functional dissociation of pre-stimulus alpha activity, P1, and N1 components. Neuroimage, 125, 25-35, 2016]. To clarify the relationships among cue predictiveness, sensory gain, and the inhibitory P1 response, we compared cue- and target-related ERPs among valid, neutral, and invalid trials with predictive (80% valid/20% invalid) or nonpredictive (50% valid/50% invalid) directional cues. Preparatory facilitation over the visual cortex contralateral to the cued side of space (lateral directing attention positivity component) was reduced during nonpredictive cueing. With predictive cues, the target-related inhibitory P1 was larger over the hemisphere contralateral to the no-target side not only in response to valid but also in response to neutral and invalid targets: This result highlights a default inhibitory hemispheric asymmetry that is independent from cued orienting of attention. With nonpredictive cues, valid targets reduced the amplitude of the inhibitory P1 over the hemisphere contralateral to the no-target side whereas invalid targets enhanced the amplitude of the same inhibitory component. Enhanced inhibition was matched with speeded reorienting to invalid targets and drop in attentional costs. These findings show that reorienting of attention is modulated by the combination of cue-related facilitatory and target-related inhibitory activity.

Spatial uncertainty improves the distribution of visual attention and the availability of sensory information for conscious report.

Picking-up and exploiting spatial and temporal regularities in the occurrence of sensory events is important for goal-directed behaviour. According to the "Predictive Coding Hypothesis" (Friston Philosophical Trans R Soc B 360(1456):815-836, 2005), these regularities are used to generate top-down predictions that are constantly compared with actual sensory events. In a previous study with the Attentional Blink (AB) paradigm, we showed that the temporal and probabilistic uncertainty of T2s that are presented outside the Attentional Blink period, i.e. at least 400 ms after T1, improves the conscious report of T2 that are presented inside the AB. The study of ERP correlated showed that this improvement was associated with a prolonged storage of pre-conscious T2 traces in extra-striate areas (Lasaponara et al. Cortex 71:15-33, 2015). Here, we tested whether variations in the probabilistic cueing of the position of a primary T1 visual target in a 4 × 4 letter array, modulate the retention of memory traces evoked by secondary letter targets (T2) that were presented in other positions of the array. Most important, in each trial, the identity of T2 was specified to participants upon disappearance of the array. We show that high probabilistic cueing facilitates T1 detection and improves the corresponding sensitivity index (d'). In contrast, retention and conscious report of secondary targets (T2) improves when the probabilistic cueing of T1 position is poor. These results suggest that uncertainty in the upcoming position of primary targets boosts the strength of memory traces evoked by secondary targets and improves the possibility that traces of secondary targets gain full access to conscious processing.

Pointing movements and visuo-spatial working memory in a joint setting: the role of motor inhibition.

Previous studies have shown that, under specific conditions, arrays that have been pointed at encoding are recognized better than passively viewed ones. According to one interpretation, the superior recognition of pointed-to arrays can be explained by the motor inhibition of passively viewed arrays. The present study sought to determine whether a similar motor inhibition can be induced also when the participants observed a co-actor perform the pointing movements. Participants were presented with two spatial arrays, one of which was encoded via observation only (the no-move array), while the other was encoded with pointing movements (the move array); movements were performed either by the participant or by the experimenter. Experiment 1 replicated the advantage of self-pointed arrays over passively viewed arrays. Experiment 2 showed that, when participants passively observed the pointing movements performed by the experimenter, move arrays were recognized no better than no-move arrays. Finally, Experiment 3 demonstrated that, in a joint-action condition in which participants alternated with the experimenter in making pointing movements, the advantage of experimenter-pointed arrays over passively viewed arrays was significant and similar in size to the advantage produced by self-performed movements. Importantly, a series of cross-experiment comparisons indicated that the higher recognition of both self- and experimenter-pointed arrays in Experiment 3 could be explained by the motor inhibition of no-move arrays. We propose that, in a joint condition, the pointing movements performed by the experimenter were represented in the same functional way as self-performed movements and that this produced the motor inhibition of passively viewed arrays.

The attentional boost effect enhances the recognition of bound features in short-term memory.

In the Attentional Boost Effect (ABE), images or words encoded with unrelated to-be-responded targets are later remembered better than images or words encoded with to-be-ignored distractors. In the realm of short-term memory, the ABE has been previously shown to enhance the short-term recognition of single-feature stimuli. The present study replicated this finding and extended it to a condition requiring the encoding and retention of colour-shape associations. Across four experiments, participants studied arrays of four coloured squares (the colour-only condition), four gray shapes (the shape-only condition) or four coloured shapes (the binding condition), paired with either a target letter (to which participants had to respond by pressing the spacebar) or a distractor letter (for which no response was required). After a short delay, they were presented with a probe array and asked to decide whether it matched or not the encoded array. Results showed that, in all conditions, the recognition of target-paired arrays was significantly better than the recognition of distractor-paired arrays. These findings suggest that the ABE can enhance feature binding.

The Attentional-SNARC effect 16 years later: no automatic space-number association (taking into account finger counting style, imagery vividness, and learning style in 174 participants).

The Attentional-SNARC effect (Att-SNARC) originally described by Fischer et al. (Nat Neurosci 6(6):555, 2003), consists of faster RTs to visual targets in the left side of space when these are preceded by small-magnitude Arabic cues at central fixation and by faster RTs to targets in the right side of space when these are preceded by large-magnitude cues. Verifying the consistency and reliability of this effect is important, because the effect would suggest an inherent association between the representation of space and that of number magnitude, while a number of recent studies provided no positive evidence in favour of the Att-SNARC and the inherency of this association (van Dijck et al. in Q J Exp Psychol 67(8):1500-1513, 2014; Zanolie and Pecher in Front Psychol 5:987, 2014; Fattorini et al. in Cortex 73:298-316, 2015; Pinto et al. in Cortex, DOI:10.1016/j.cortex.2017.12.015, 2018). Here, we re-analysed Att-SNARC data that we have collected in 174 participants over different studies run in our laboratory. Most important, in a subsample of 79 participants, we also verified whether the strength and reliability of the Att-SNARC is eventually linked inter-individual variations in finger counting style, imagery vividness, and verbal/visual learning style. We found no evidence for the Att-SNARC effect or for the influence of finger counting style, imagery vividness, and learning style on its direction or consistency. These results confirm no inherent link between orienting of spatial attention and representation of number magnitudes. We propose that this link is rather determined by the joint use of spatial and number magnitude or parity codes in the performance of the numerical task at hand.

Collaborative remembering reduces suggestibility: A study with the Gudjonsson Suggestibility Scale.

Collaboration during the retrieval phase can have both negative and positive effects (referred to as collaborative inhibition and error pruning, respectively) on emotional and eyewitness memory. To further elucidate these issues, the present experiment used the Gudjonsson Suggestibility Scale to investigate the question of whether collaborative remembering reduced post-event suggestibility. Collaborative and nominal pairs listened to the GSS2, provided immediate and delayed (after 30 min) free recalls, and answered a series of leading questions before or after receiving a negative feedback about their performance. We found no evidence of collaborative inhibition in the immediate and delayed free recall tasks. Importantly, however, collaborative pairs produced less confabulated elements in the free recall tasks, were considerably less prone to give in to leading questions (both before and after receiving the negative feedback), and exhibited lower levels of Total Suggestibility, compared to both nominal and individual dyads. Taken together, these results support the conclusion that collaboration can have a beneficial influence on eyewitnesses' accuracy, by strengthening their resistance to post-event suggestibility.

Not all identification tasks are born equal: testing the involvement of production processes in perceptual identification and lexical decision.

The distinction between identification and production processes suggests that implicit memory should require more attention resources when there is a competition between alternative solutions during the test phase. The present two experiments assessed this hypothesis by examining the effects of divided attention (DA) at encoding on the high- and low-response-competition versions of perceptual identification (Experiment 1) and lexical decision (Experiment 2). In both experiments, words presented in the high-response-competition condition had many orthographic neighbours and at least one higher-frequency neighbour, whereas words presented in the low-response-competition condition had few orthographic neighbours and no higher-frequency neighbour. Consistent with the predictions of the identification/production distinction, Experiment 1 showed that DA reduced repetition priming in the high-, but not in the low-response-competition version of perceptual identification; in contrast, DA had comparable effects in the two versions of lexical decision (Experiments 2). These findings provide the first experimental evidence in support of the hypothesis that perceptual identification, a task nominally based on identification processes, might involve a substantive production component.

Divided attention enhances the recognition of emotional stimuli: evidence from the attentional boost effect.

The present study examined predictions of the early-phase-elevated-attention hypothesis of the attentional boost effect (ABE), which suggests that transient increases in attention at encoding, as instantiated in the ABE paradigm, should enhance the recognition of neutral and positive items (whose encoding is mostly based on controlled processes), while having small or null effects on the recognition of negative items (whose encoding is primarily based on automatic processes). Participants were presented a sequence of negative, neutral and positive stimuli (pictures in Experiment 1, words in Experiment 2) associated to target (red) squares, distractor (green) squares or no squares (baseline condition). They were told to attend to the pictures/words and simultaneously press the spacebar of the computer when a red square appeared. In a later recognition task, stimuli associated to target squares were recognised better than stimuli associated to distractor squares, replicating the standard ABE. More importantly, we also found that: (a) the memory enhancement following target detection occurred with all types of stimuli (neutral, negative and positive) and (b) the advantage of negative stimuli over neutral stimuli was intact in the DA condition. These findings suggest that the encoding of negative stimuli depends on both controlled (attention-dependent) and automatic (attention-independent) processes.

Collaboration in implicit memory: evidence from word-fragment completion and category exemplar generation.

Recent studies have begun to investigate the effects of collaboration on explicit tests such as free recall, cued recall, and recognition. In contrast, little is known about the impact of this variable on implicit memory. To bridge this gap, the present study compared the performance of nominal and collaborative groups in two implicit memory tasks-word-fragment completion (WFCT) and category exemplar generation (CEGT). Both the disruption-of-individual-retrieval-strategies and the retrieval blocking hypotheses predicted no significant negative effects of collaboration on repetition priming; in contrast, the retrieval inhibition hypothesis predicted lower priming in collaborative than in nominal groups in both tasks. The results supported the former hypotheses, because priming scores in the WFCT and the CEGT did not differ between collaborative and individual groups. Interestingly; however, a significant collaborative inhibition was obtained in the CEGT (but not in the WFCT) when considering the raw proportions of studied and unstudied exemplars generated. The latter finding might indicate that the performance of collaborative groups can be significantly impaired by the disruption of within-category order resulting from the exposure to the exemplars generated by other group members, even when participants do not explicitly attempt to retrieve the stimuli presented at encoding.

Testing the Identification/Production Hypothesis of Implicit Memory in Schizophrenia: The Role of Response Competition.

OBJECTIVES: Previous evidence indicates that patients with schizophrenia exhibit reduced repetition priming in production tasks (in which each response cue engenders a competition between alternative responses), but not in identification tasks (in which each response cue allows a unique response). However, cross-task comparisons may lead to inappropriate conclusions, because implicit tests vary on several dimensions in addition to the critical dimension of response competition. The present study sought to isolate the role of response competition, by varying the number of solutions in the context of the same implicit tasks. METHODS: Two experiments investigated the performance of patients with schizophrenia and healthy controls in the high-competition and low-competition versions of word-stem completion (Exp.1) and verb generation (Exp.2). RESULTS: Response competition affected both the proportions of stems completed (higher to few-solution than to many-solution stems) and the reaction times of verb generation (slower to nouns having no dominant verb associates than to nouns having one dominant verb associate). Patients with schizophrenia showed significant (non-zero) priming in both experiments: crucially, the magnitude of this facilitation was equivalent to that observed in healthy controls and was not reduced in the high-competition versions of the two tasks. CONCLUSIONS: These findings suggest that implicit memory is spared in schizophrenia, irrespective of the degree of response competition during the retrieval phase; in addition, they add to the ongoing debate regarding the validity of the identification/production hypothesis of repetition priming.

Implicit memory in schizophrenia: a meta-analysis.

OBJECTIVE: Previous studies examining implicit memory in schizophrenia yielded inconsistent results. The present meta-analysis aimed at determining whether, compared to healthy controls, schizophrenic patients: (a) exhibited reduced priming in the whole set of studies; (b) were differentially impaired in conceptual/perceptual and production/identification tests; and (c) were less efficient in the use of semantic encoding processes. METHOD: A systematic search in PsycINFO and PubMed led to the selection of 22 critical studies (31 effect sizes), comparing repetition priming in 836 schizophrenic patients and 760 healthy controls. Moderators were assessed by classifying implicit tasks into the perceptual/conceptual and identification/production categories, and by distinguishing between perceptual and conceptual encoding instructions. RESULTS: Overall, implicit memory was slightly, but significantly, impaired in schizophrenia (d=0.179). Patients exhibited reduced priming in conceptually-driven tasks (d=0.447), but intact priming in perceptually-driven tasks (d=0.080). No significant difference was observed between identification and production priming (d=0.064 vs. d=0.243). Finally, priming in schizophrenic patients was significantly lower than that of controls when the encoding task required the analysis of the conceptual properties of the stimuli (d=0.261). CONCLUSION: Results suggest that schizophrenia is associated with a specific deficit in the use of conceptual processes, both at encoding and at retrieval. In contrast with theoretical expectations, high levels of response competition did not disproportionately impair the patients' performance.

Memory in pregnancy and post-partum: Item specific and relational encoding processes in recall and recognition.

It has been recently proposed that pregnant women would perform memory tasks by focusing more on item-specific processes and less on relational processing, compared to post-partum women (Mickes, Wixted, Shapiro & Scarff, ). The present cross-sectional study tested this hypothesis by directly manipulating the type of encoding employed in the study phase. Pregnant, post-partum and control women either rated the pleasantness of word meaning (which induced item-specific elaboration) or named the semantic category to which they belonged (which induced relational elaboration). Memory for the encoded words was later tested in free recall (which emphasizes relational processing) and in recognition (which emphasizes item-specific processing). In line with Mickes et al.'s () conclusions, pregnant women in the item-specific condition performed worse than post-partum women in the relational condition in free recall, but not in recognition. However, compared to the other two groups, pregnant women also exhibited lower recognition accuracy in the item-specific condition. Overall, these results confirm that pregnant women rely on relational encoding less than post-partum women, but additionally suggest that the former group might use item-specific processes less efficiently than post-partum and control women.

Running rescues defective adult neurogenesis by shortening the length of the cell cycle of neural stem and progenitor cells.

Physical exercise increases the generation of new neurons in adult neurogenesis. However, only few studies have investigated the beneficial effects of physical exercise in paradigms of impaired neurogenesis. Here, we demonstrate that running fully reverses the deficient adult neurogenesis within the hippocampus and subventricular zone of the lateral ventricle, observed in mice lacking the antiproliferative gene Btg1. We also evaluated for the first time how running influences the cell cycle kinetics of stem and precursor subpopulations of wild-type and Btg1-null mice, using a new method to determine the cell cycle length. Our data show that in wild-type mice running leads to a cell cycle shortening only of NeuroD1-positive progenitor cells. In contrast, in Btg1-null mice, physical exercise fully reactivates the defective hippocampal neurogenesis, by shortening the S-phase length and the overall cell cycle duration of both neural stem (glial fibrillary acidic protein(+) and Sox2(+)) and progenitor (NeuroD1(+)) cells. These events are sufficient and necessary to reactivate the hyperproliferation observed in Btg1-null early-postnatal mice and to expand the pool of adult neural stem and progenitor cells. Such a sustained increase of cell proliferation in Btg1-null mice after running provides a long-lasting increment of proliferation, differentiation, and production of newborn neurons, which rescues the impaired pattern separation previously identified in Btg1-null mice. This study shows that running positively affects the cell cycle kinetics of specific subpopulations of newly generated neurons and suggests that the plasticity of neural stem cells without cell cycle inhibitory control is reactivated by running, with implications for the long-term modulation of neurogenesis.

Is conceptual implicit memory impaired in schizophrenia? Evidence from lexical decision and category verification.

INTRODUCTION: Implicit memory tasks differ along two orthogonal dimensions, tapping the relative involvement of perceptual/conceptual and identification/production processes. Previous studies have documented a dissociation between perceptual (spared) and conceptual (impaired) implicit memory, using in the latter case a production task (category exemplar generation), in which there is high response competition during the retrieval phase. The present study sought to determine whether the perceptual/conceptual dissociation held when comparing two identification tasks, in which there is no response competition at retrieval. METHODS: In two experiments, repetition priming was assessed in 44 schizophrenic patients and 46 healthy controls in lexical decision (a test based on perceptual identification processes) and category verification (a test based on conceptual identification processes). RESULTS: Schizophrenic patients achieved a priming as high as that of controls in the lexical decision task. In contrast, only controls exhibited significant priming in the category verification task. CONCLUSIONS: It is concluded that schizophrenia is associated with a specific deficit in conceptual implicit memory, irrespective of the degree of response competition in the test phase.

Loss of NGF-TrkA signaling from the CNS is not sufficient to induce cognitive impairments in young adult or intermediate-aged mice.

Many molecules expressed in the CNS contribute to cognitive functions either by modulating neuronal activity or by mediating neuronal trophic support and/or connectivity. An ongoing discussion is whether signaling of nerve growth factor (NGF) through its high-affinity receptor TrkA contributes to attention behavior and/or learning and memory, based on its expression in relevant regions of the CNS such as the hippocampus, cerebral cortex, amygdala and basal forebrain. Previous animal models carrying either a null allele or transgenic manipulation of Ngf or Trka have proved difficult in addressing this question. To overcome this problem, we conditionally deleted Ngf or Trka from the CNS. Our findings confirm that NGF-TrkA signaling supports survival of only a small proportion of cholinergic neurons during development; however, this signaling is not required for trophic support or connectivity of the remaining basal forebrain cholinergic neurons. Moreover, comprehensive behavioral analysis of young adult and intermediate-aged mice lacking NGF-TrkA signaling demonstrates that this signaling is dispensable for both attention behavior and various aspects of learning and memory.

Trust in science and belief in misinformation mediate the effects of political orientation on vaccine hesitancy and intention to be vaccinated.

In previous studies, anti-vaccination attitudes have been attributed either to far-right voters or to both far-left and far-right voters. The present study investigated the associations of political orientation with vaccine hesitancy and intention to be vaccinated against COVID-19, and the potential mediating roles of trust in science and belief in misinformation. A total of 750 Italian respondents completed an online questionnaire in the period between the second and the third wave of COVID-19 (from 9th March to 9th May 2021). The results showed that political orientation had both direct and indirect associations with vaccine hesitancy and vaccine intention, mediated by trust in science and belief in misinformation. Specifically, right-wing adherents were less trustful of scientists and believed in COVID-19-related misinformation more than left-wing adherents, and these two factors accounted for their higher vaccine hesitancy and reduced willingness to receive an anti-COVID-19 vaccination. Our findings are in line with the predictions of the mindsponge theory and suggest that communicative campaigns aimed at improving the rates of vaccine acceptance in right-wing adherents should be specifically focused on enhancing trust in science and reducing belief in misinformation.

The binding of negative emotional stimuli with spatial information in working memory: A possible role for the episodic buffer.

Introduction: Remembering where negative events occur has undeniable adaptive value, however, how these memories are formed remains elusive. We investigated the role of working memory subcomponents in binding emotional and visuo-spatial information using an emotional version of the object relocation task (EORT). Methods: After displaying black rectangles simultaneously, emotional pictures (from the International Affective Pictures System) appeared sequentially over each rectangle. Participants repositioned the rectangles as accurately as possible after all stimuli had disappeared. During the EORT encoding phase, a verbal trail task was administered concurrently to selectively interfere with the central executive (CE). The immediate post-encoding administration of an object feature-report task was used to interfere with the episodic buffer (EB). Results: Only the EB-interfering task prevented the emotion-enhancing effect of negative pictures. The latter effect was not observed with a concurrent executive task. Discussion: Overall, our findings suggest that pre-attentive automatic processes are primarily involved in binding emotional and visuo-spatial information in the EB.

Autobiographical memory in contact tracing: evidence from the COVID-19 pandemic.

Introduction: The recent COVID-19 pandemic has compelled various governments to trace all contacts of a confirmed case, as well as to identify the locations visited by infected individuals. This task, that requires the activation of our autobiographical memories, can make a difference in the spread of the contagion and was based primarily on telephone interviews with infected people. In this study, we examined whether participants were able to provide contact tracing information and whether their memories were influenced by salient events occurring during the initial phases of the pandemic. Methods: Participants were asked to fill in an online standardized form in which they recounted every day of the 2 weeks before, reporting as much information as possible. The time period selected included, among other things, the day on which the Italian government issued the decree initiating the COVID-19 lockdown. The task was completed twice, the first time relying solely on their memory, and the second time using external aids (diaries, mobile phones etc.). Reports were then coded using a scheme that segmented accounts into informational details, divided into two broad categories, internal and external. Results: Our findings showed that (i) the use of external aids was effective only when participants had to recall the day furthest away or if to-be-recalled events have low distinctiveness, and (ii) memories of internal details were recalled better than memories of external details. Participants were overall accurate and reported a large amount of information about people and places. However, because of the connection with key pandemic-related events, the effect was somewhat stronger on specific days (e.g., the day in which the lockdown was announced). Discussion: The results of this work could provide a useful tool for improving the design of contact tracing procedures in the event of an unwanted future public health crisis caused by a highly infectious agent.

Extinction after retrieval: effects on the associative and nonassociative components of remote contextual fear memory.

Long-lasting memories of adverse experiences are essential for individuals' survival but are also involved, in the form of recurrent recollections of the traumatic experience, in the aetiology of anxiety diseases (e.g., post-traumatic stress disorder [PTSD]). Extinction-based erasure of fear memories has long been pursued as a behavioral way to treat anxiety disorders; yet, such a procedure turns out to be transient, context-dependent, and ineffective unless it is applied immediately after trauma. Recent evidence indicates that, in both rats and humans, extinction training can prevent the return of fear if administered within the reconsolidation window, when memories become temporarily labile and susceptible of being updated. Here, we show that the reconsolidation-extinction procedure fails to prevent the spontaneous recovery of a remote contextual fear memory in a mouse model of PTSD, as well as the long-lasting behavioral abnormalities induced by traumatic experience on anxiety and in both social and cognitive domains (i.e., social withdrawal and spatial learning deficits). Such a failure appears to be related to the ineffectiveness of the reconsolidation-extinction procedure in targeting the pathogenic process of fear sensitization, a nonassociative component of traumatic memory that causes animals to react aberrantly to harmless stimuli. This indicates fear sensitization as a major target for treatments aimed at mitigating anxiety and the behavioral outcomes of traumatic experiences.