Collaborative encoding with a new categorization task: a contribution to collaborative memory research.

Collaborative memory research has focused primarily on the effects of collaboration at recall with collaboration during encoding receiving less attention. In the present study, collaboration was investigated both at encoding and at retrieval to determine its effects and possible interactions. The aim was to clarify whether the collaborative inhibition effect depended on whether the encoding was with the same or with a different partner. A total of 320 participants (160 Italian and 160 Spanish undergraduate students) were administered a modified version of the collaborative memory paradigm with a new categorization task of verbal affective stimuli at encoding. Specifically, they were asked to classify 90 printed words into 6 categories, so as to have 15 words in each category and then did two recall tasks. Participants were assigned to one of five possible conditions according to encoding (collaborative, individual) and recall (collaborative with the same partner, with another partner, and individual). Results show a collaborative encoding deficit and the classic collaborative inhibition effect independently of whether the encoding was collaborative or individual and even in a collaborative recall group that showed a degree of recall output organization comparable to that of the individual recall group. These results are not wholly consistent with a retrieval disruption explanation and are discussed according to divided attention during collaborative recall and how it may contribute to the collaborative inhibition effect.

Metacognition in working memory: Confidence judgments during an n-back task.

Metacognition in working memory (WM) has received less attention than episodic memory, and few studies have investigated confidence judgements while carrying out a verbal WM task. The present study investigated whether individuals are aware of their own level of performance while carrying out an ongoing verbal WM task, and whether judgments of confidence are sensitive to factors that determine WM performance. A verbal n-back task was adapted to obtain confidence judgments on a trial-by-trial basis. Memory load and lure interference were manipulated. Results showed that metacognition judgments were affected by memory load and levels of interference just as performance accuracy. Even when judgments were sensitive to memory factors, participants were overconfident and generally showed poor metacognitive accuracy at discriminating between erroneous and accurate responses. Results are discussed in terms of possible cues contributing to metacognitive judgements during an ongoing WM task and reasons for WM metacognitive accuracy.

Development and Validation of a Short Form of the Geriatric Anxiety Scale (GAS-12) among Italian Older Adults.

OBJECTIVES: We developed a new Italian short version of the Geriatric Anxiety Scale (GAS-12) and evaluated its psychometric properties. The GAS-12 specifically screens for anxiety symptoms in the Italian older adult population by identifying items that best discriminate anxiety in this population. METHODS: In Study 1, we administered the full-length Italian translation of the GAS to 517 older adults and used item response theory to identify the most discriminating items and to develop the short form used in Study 2. In Study 2, we evaluated the functioning of the new short form of the questionnaire in a new sample of 427 older adults using Confirmatory factor analysis. RESULTS: Analyses indicated 12 items that discriminated well between anxious and non-anxious participants and distributed along the latent continuum of each trait. The GAS-12 fits a three-factor structure. There was also evidence for convergent and divergent validity. CONCLUSIONS: The Italian GAS-12 appears to be a useful instrument for the quantitative screening of anxiety in Italian older adults. CLINICAL IMPLICATIONS: Anxiety imposes significant impairment thus making imperative the screening and assessment of anxiety symptoms. The GAS-12 is particularly indicated with limited time and many scales in a clinical assessment or research protocols.

Dopamine-related polymorphisms and Affective Working Memory in aging.

The neurotransmitter dopamine (DA) is a key regulatory component of executive functioning and dysfunction in dopaminergic circuity has been shown to result in impaired working memory. Studies have identified multiple common genetic variants suggested to functionally impact the DA system and behaviorally alter working memory performance. Here, we aimed to develop a predictive model of affective working memory and to examine whether specific combinations of polymorphisms differently influence later encoding processes in affective working memory. Specifically, we examined the effects of the dopamine D2 and D1 receptors and Catechol-O-methyltransferase (COMT), on affective working memory in 155 older adults. Our model identified genotype variants, and scores on the Mini-Mental State exam and Geriatric depression scales as significant influencers in the predictive model whereas behavioral results showed specific patterns of performance linked to valence and string length but not to specific genetic variants. That is, all participants remembered a more positive words compared to negative and neutral words when remembering short strings of 3 or 4 words whereas performance on long strings, 5 or 6 words, revealed a more general affective enhancement independent of genotype. These findings are some of the first to investigate the effects dopaminergic enzyme and receptor interactions on affective working memory.

Memory for item-location bindings is enhanced in older adults with appetitive motivationally laden pictures.

Both the selection and consumption of food are biologically necessary for survival. Consequently, individuals may consider food as a primary and biologically relevant stimulus. In addition, recent findings support specific patterns of food preference during the lifespan development. Indeed, the preference for sweet taste largely observed in newborns and children seems to decline in young adults and then re-emerge again in older adults. This motivational preference for sweet food in older adults may be potentially useful in the cognitive domain since many studies have found that motivationally or emotionally laden information is more likely to be detected, stored in memory and retrieved better than neutral information. To address this issue, we designed an item-location binding task with sweet food, savory food and object pictures, and asked young and older adults to maintain information in working memory and respond based on memory for either individual features or feature combination (i.e., identification, location, or combined identification + location information). Results evidenced a significant enhancement of older adults' performance in the binding of motivationally relevant stimuli and their location, evidencing the potential usefulness of motivationally laden stimuli in promoting more effective binding processes and probably, more general working memory processes.

Crossmodal congruency effects between sound and food pictures in a forced-choice task.

Research using short musical sequences and musical tracks created by means of computer algorithms has demonstrated that individuals with or without musical skills can match these soundtracks to specific tastes with above-chance accuracy. More recently, a study that investigated implicit effects associated with crossmodal congruency/incongruency between auditory cues and food images found that such soundtracks are effective in eliciting facilitating effects of taste quality classification with congruent food images as well. In the present study, we tested whether this crossmodal congruency between auditory cues and food images may also influence food image choice by means of a forced-choice task. We selected and used sweet and salty soundtracks as stimuli and food images including both low- and high-calorie exemplars and asked participants to select which food they would prefer to eat (one sweet and one salty) while listening to the soundtracks. We found a general greater proportion of food choices in the soundtracks matching tastes conditions, and that soundtracks matching tastes are effective in influencing congruent food image choices, supporting previous research and adding new interesting outcomes.

The effects of music on spatial reasoning.

Studies on the effects of music on spatial reasoning report conflicting results. Some studies show slight effects, and others show no effects but few seem to replicate the strong findings of the first study published in Rauscher et al. Nature, 365(6447), 611-612, (1993). Nonetheless, the debate about the performance enhancing "Mozart effect" remains to be of great interest. In this study, we manipulated different physical parameters of sound traces (amplitude and frequency) to investigate whether particular dimensions may explain the enhancement effects found in spatial tasks following music listening. To this end, we asked 179 undergraduates and 183 older adults to listen to 5-min sound traces (Mozart KV 448, amplitude modulation tone, frequency modulation tone, white noise) and then complete a spatial reasoning task. In particular, results showed that repetitive frequency changes, as occurring in Mozart's melodies or in a frequency modulation tone, enhance performance.

Emotional faces influence evaluation of natural and transformed food.

Previous evidence showed the presence of a straight relationship between feeding behavior and emotions. Despite that, no studies have focused on the influence of emotional faces on food processing. In our study, participants were presented with 72 couples of visual stimuli composed of a neutral, happy, or disgusted faces (5000 ms duration in Experiment 1, adaptation; 150 ms in Experiment 2, priming) followed by a food stimulus (1500 ms). Food stimuli were grouped in pleasant foods, further divided in natural and transformed, and unpleasant rotten foods. The task consisted in judging the food valence (as 'pleasant' or 'unpleasant') by keypress. Results showed a different pattern of response based on the transformation level of food. In general, the evaluation of natural foods was more rapid compared with transformed foods, maybe for their simplicity and healthier perception. In addition, transformed foods yielded incongruent responses with respect to the preceding emotional face, whereas natural foods yielded congruent responses with respect to it. These effects were independent of the duration of the emotional face (i.e., adaptation or priming paradigm) and may depend on pleasant food stimuli salience.

Author Correction: Emotional faces influence evaluation of natural and transformed food.

This article unfortunately contained two mistakes.

Sex-specific effects of posture on the attribution of handedness to an imagined agent.

In a series of previous studies, we found that when participants were required to imagine another person performing a manual action, they imagined a significantly higher proportion of actions performed with their dominant rather than non-dominant hand, which indicates that shared motor representations between the self and the other are involved also during the imagination of others' actions. Interestingly, the activation of lateralized body-specific motor representations (as indexed by the congruence between the participant's handedness and the imagined person's handedness) appeared to be affected by the visual perspective adopted and participants' handedness. Given that past literature indicates that incongruent or unnatural postures interfere with motor imagery, we tested 480 right-handed participants to investigate whether subjects holding their right hand behind their back would have imagined right-handed actions less frequently than those holding their left hand behind their back. Moreover, we examined the effects of participant's sex, action category (simple or complex) and hand shape (open or fist). Contrary to our prediction, female participants holding their right hand behind their back imagined right-handed actions more frequently than those holding their left hand behind their back, whereas no significant effect was observed in male participants. We propose that the muscle contraction needed to keep a hand behind the back could activate the motor representations of that hand so as to increase the likelihood of imagining an action performed with the corresponding hand. Moreover, the sex difference observed is consistent with the greater use of embodied strategies by females than by males.

Colored valence in a lexical decision task.

Color influences behavior, from the simplest to the most complex, through controlled and more automatic information elaboration processes. Nonetheless, little is known about how and when these highly interconnected processes interact. This study investigates the interaction between controlled and automatic processes during the processing of color information in a lexical decision task. Participants discriminated stimuli presented in different colors (red, blue, green) as words or pseudowords. Results showed that while color did not affect the faster and more accurate recognition of words compared to pseudowords, performance was influenced when examining words and pseudowords separately. Pseudowords were recognized faster when presented in blue or red, suggesting a potential influence of evolutionary color preferences when processing is not guided by more controlled processes. With words, emotional enhancement effects were found, with a preference for green independent of valence. These results suggest that controlled and more automatic processes do interact when processing color information according to stimulus type and task.

Atrophy of hippocampal subfields and amygdala nuclei in subjects with mild cognitive impairment progressing to Alzheimer's disease.

The hippocampus and amygdala are the first brain regions to show early signs of Alzheimer's Disease (AD) pathology. AD is preceded by a prodromal stage known as Mild Cognitive Impairment (MCI), a crucial crossroad in the clinical progression of the disease. The topographical development of AD has been the subject of extended investigation. However, it is still largely unknown how the transition from MCI to AD affects specific hippocampal and amygdala subregions. The present study is set to answer that question. We analyzed data from 223 subjects: 75 healthy controls, 52 individuals with MCI, and 96 AD patients obtained from the ADNI. The MCI group was further divided into two subgroups depending on whether individuals in the 48 months following the diagnosis either remained stable (N = 21) or progressed to AD (N = 31). A MANCOVA test evaluated group differences in the volume of distinct amygdala and hippocampal subregions obtained from magnetic resonance images. Subsequently, a stepwise linear discriminant analysis (LDA) determined which combination of magnetic resonance imaging parameters was most effective in predicting the conversion from MCI to AD. The predictive performance was assessed through a Receiver Operating Characteristic analysis. AD patients displayed widespread subregional atrophy. MCI individuals who progressed to AD showed selective atrophy of the hippocampal subiculum and tail compared to stable MCI individuals, who were undistinguishable from healthy controls. Converter MCI showed atrophy of the amygdala's accessory basal, central, and cortical nuclei. The LDA identified the hippocampal subiculum and the amygdala's lateral and accessory basal nuclei as significant predictors of MCI conversion to AD. The analysis returned a sensitivity value of 0.78 and a specificity value of 0.62. These findings highlight the importance of targeted assessments of distinct amygdala and hippocampus subregions to help dissect the clinical and pathophysiological development of the MCI to AD transition.

Novel Approaches to Memory and Aging: The Editorial.

Heightened average life expectancy, which is increasing the number of older adults destined to live alone in the future, is forcing society to acknowledge the strong positive correlation between health costs and age [...].

Atrophy of specific amygdala subfields in subjects converting to mild cognitive impairment.

Introduction: Accumulating evidence indicates that the amygdala exhibits early signs of Alzheimer's disease (AD) pathology. However, it is still unknown whether the atrophy of distinct subfields of the amygdala also participates in the transition from healthy cognition to mild cognitive impairment (MCI). Methods: Our sample was derived from the AD Neuroimaging Initiative 3 and consisted of 97 cognitively healthy (HC) individuals, sorted into two groups based on their clinical follow-up: 75 who remained stable (s-HC) and 22 who converted to MCI within 48 months (c-HC). Anatomical magnetic resonance (MR) images were analyzed using a semi-automatic approach that combines probabilistic methods and a priori information from ex vivo MR images and histology to segment and obtain quantitative structural metrics for different amygdala subfields in each participant. Spearman's correlations were performed between MR measures and baseline and longitudinal neuropsychological measures. We also included anatomical measurements of the whole amygdala, the hippocampus, a key target of AD-related pathology, and the whole cortical thickness as a test of spatial specificity. Results: Compared with s-HC individuals, c-HC subjects showed a reduced right amygdala volume, whereas no significant difference was observed for hippocampal volumes or changes in cortical thickness. In the amygdala subfields, we observed selected atrophy patterns in the basolateral nuclear complex, anterior amygdala area, and transitional area. Macro-structural alterations in these subfields correlated with variations of global indices of cognitive performance (measured at baseline and the 48-month follow-up), suggesting that amygdala changes shape the cognitive progression to MCI. Discussion: Our results provide anatomical evidence for the early involvement of the amygdala in the preclinical stages of AD. Highlights: Amygdala's atrophy marks elderly progression to mild cognitive impairment (MCI).Amygdala's was observed within the basolateral and amygdaloid complexes.Macro-structural alterations were associated with cognitive decline.No atrophy was found in the hippocampus and cortex.

Motor Imagery as a Key Factor for Healthy Ageing: A Review of New Insights and Techniques.

Motor imagery (MI) describes a dynamic cognitive process where a movement is mentally simulated without taking place and holds potential as a means of stimulating motor learning and regaining motor skills. There is growing evidence that imagined and executed actions have common neural circuitry. Since MI counteracts cognitive and motor decline, a growing interest in MI-based mental exercise for older individuals has emerged. Here we review the last decade's scientific literature on age-related changes in MI skills. Heterogeneity in the experimental protocols, as well as the use of populations with unrepresentative age, is making it challenging to draw unambiguous conclusions about MI skills preservation. Self-report and behavioural tasks have shown that some MI components are preserved, while others are impaired. Evidence from neuroimaging studies revealed that, during MI tasks, older individuals hyperactivate their sensorimotor and attentional networks. Some studies have argued that this represents a compensatory mechanism, others claim that this is a sign of cognitive decline. However, further studies are needed to establish whether MI could be used as a promotion factor to improve cognitive functioning and well-being in older people.

Do Older and Younger Adults Prefer the Positive or Avoid the Negative?

Affective information is processed in different ways across one's lifespan. Explanations for this pattern of performance are multiple and range from top-down motivational shifts and cognitive control to faster bottom-up and implicit processes. In this study, we aimed to investigate implicit affective information processing and positivity effects by examining performance in a modified version of the dot-probe task across three image-pair conditions (positive/neutral; negative/neutral; and positive/negative). We examined data from 50 older adults and 50 younger adults. The results showed that affective information processing varies with age and valence and that age effects in affective processing may occur early during information processing. Positivity biases emerge in both younger and older adults. However, while younger adults seem to prioritize positive information independently of context, older adults showed this prioritization only when presented in an emotional (i.e., negative) context. Moreover, older adults showed a tendency to avoid negative information whereas younger adults showed a general bias for affective content modulated by image-pair context.

Curiosity Killed the Cat but Not Memory: Enhanced Performance in High-Curiosity States.

Curiosity benefits memory for target information and may also benefit memory for incidental information presented during curiosity states. However, it is not known whether incidental curiosity-enhanced memory depends on or is affected by the valence of the incidental information during curiosity states. Here, older and younger participants incidentally encoded unrelated face images (positive, negative, and neutral) while they anticipated answers to trivia questions. We found memory enhancements for answers to trivia questions and unrelated faces presented during high-curiosity compared with low-curiosity states in both younger and older adults. Interestingly, face valence did not modify memory for unrelated faces. This suggests processes associated with the elicitation of curiosity enhance memory for incidental information instead of valence.

A Bottom-Up Validation of the IAPS, GAPED, and NAPS Affective Picture Databases: Differential Effects on Behavioral Performance.

The concept of emotion is a complex neural and psychological phenomenon, central to the organization of human social behavior. As the result of subjective experience, emotions involve bottom-up cognitive styles responsible for efficient adaptation of human behavior to the environment based on salient goals. Indeed, bottom-up cognitive processes are mandatory for clarifying emotion-cognition interactions. Accordingly, a huge number of studies and standardized affective stimuli databases have been developed (i.e., International Affective Picture System (IAPS), Geneva Affective Picture Database (GAPED), and Nencki Affective Picture System (NAPS)). However, these neither accurately reflect the complex neural system underlying emotional responses nor do they offer a comprehensive framework for researchers. The present article aims to provide an additional bottom-up validation of affective stimuli that are independent from cognitive processing and control mechanisms, related to the implicit relevance and evolutionistic significance of stimuli. A subset of 360 images from the original NAPS, GAPED, and IAPS datasets was selected in order to proportionally cover the whole dimensional affective space. Among these, using a two-step analysis strategy, we identified three clusters ("good performance", "poor performance", and "false alarm") of stimuli with similar cognitive response profiles. Results showed that the three clusters differed in terms of arousal and database membership, but not in terms of valence. The new database, with accompanying ratings and image parameters, allows researchers to select visual stimuli independent from dimensional/discrete-categories, and provides information on the implicit effects triggered by such stimuli.

Neuroimaging the consciousness of self: Review, and conceptual-methodological framework.

We review neuroimaging research investigating self-referential processing (SRP), that is, how we respond to stimuli that reference ourselves, prefaced by a lexical-thematic analysis of words indicative of "self-feelings". We consider SRP as occurring verbally (V-SRP) and non-verbally (NV-SRP), both in the controlled, "top-down" form of introspective and interoceptive tasks, respectively, as well as in the "bottom-up" spontaneous or automatic form of "mind wandering" and "body wandering" that occurs during resting state. Our review leads us to outline a conceptual and methodological framework for future SRP research that we briefly apply toward understanding certain psychological and neurological disorders symptomatically associated with abnormal SRP. Our discussion is partly guided by William James' original writings on the consciousness of self.

"Octave illusion" or "Deutsch's illusion"?

The "Deutsch's illusion" occurs in most people when a dichotic pair of tones spaced an octave apart is presented repeatedly in alternation, so that when the right ear receives the high tone, the left ear receives the low tone, and vice versa. The illusory percept consists typically in a single low tone heard at one ear alternating with a single high tone heard at the other ear. Here, we investigate whether the frequency interval between the tones and their duration play a role in the perception of the illusion. By testing 74 subjects we demonstrate that the illusion is not confined to tones spaced an octave apart but it is perceivable also with tones separated by a major seventh, a minor ninth, a major ninth, and a minor tenth. Regarding duration, the present results show that the illusion is stronger with tones lasting 500 than 200 ms. The present results suggest that the perceptual mechanisms at the basis of the illusion are not strictly linked to the frequency relationships between the dichotic tones.