Alberto Di Domenico

Effects of Transcranial Direct Current Stimulation on episodic memory related to emotional visual stimuli.

The present study investigated emotional memory following bilateral transcranial electrical stimulation (direct current of 1 mA, for 20 minutes) over fronto-temporal cortical areas of healthy participants during the encoding of images that differed in affective arousal and valence. The main result was a significant interaction between the side of anodal stimulation and image emotional valence. Specifically, right anodal/left cathodal stimulation selectively facilitated the recall of pleasant images with respect to both unpleasant and neutral images whereas left anodal/right cathodal stimulation selectively facilitated the recall of unpleasant images with respect to both pleasant and neutral images. From a theoretical perspective, this double dissociation between the side of anodal stimulation and the advantage in the memory performance for a specific type of stimulus depending on its pleasantness supported the specific-valence hypothesis of emotional processes, which assumes a specialization of the right hemisphere in processing unpleasant stimuli and a specialization of the left hemisphere in processing pleasant stimuli. From a methodological point of view, first we found tDCS effects strictly dependent on the stimulus category, and second a pattern of results in line with an interfering and inhibitory account of anodal stimulation on memory performance. These findings need to be carefully considered in applied contexts, such as the rehabilitation of altered emotional processing or eye-witness memory, and deserve to be further investigated in order to understand their underlying mechanisms of action.

Aging and emotional expressions: is there a positivity bias during dynamic emotion recognition?

In this study, we investigated whether age-related differences in emotion regulation priorities influence online dynamic emotional facial discrimination. A group of 40 younger and a group of 40 older adults were invited to recognize a positive or negative expression as soon as the expression slowly emerged and subsequently rate it in terms of intensity. Our findings show that older adults recognized happy expressions faster than angry ones, while the direction of emotional expression does not seem to affect younger adults’ performance. Furthermore, older adults rated both negative and positive emotional faces as more intense compared to younger controls. This study detects age-related differences with a dynamic online paradigm and suggests that different regulation strategies may shape emotional face recognition.

Noradrenergic modulation of emotional memory in aging

Interest in the role of the noradrenergic system in the modulation of emotional memories has recently increased. This study briefly reviews this timely line of research with a specific focus on aging. After having identified surprisingly few studies that investigated emotional memory in older adults from a neurobiological perspective, we found a significant interaction between noradrenergic activity and emotional memory enhancement in older adults. This pattern of data are explained both in terms of a top-down modulation of behavioral processes (e.g., changes in priority and individual goals) and in terms of greater activity of noradrenergic system during aging. Altogether, both behavioral and genetic variations studies (e.g., Alpha 2 B Adrenoceptor genotype) have shown that healthy older adults are able to circumvent or minimize the experience of negative emotions and stabilize or even enhance positive emotional experiences. Future studies are highly warranted to better clarify the relationship between noradrenaline and emotional memories in the aging brain.

The Relation between Self-Reported Empathy and Motor Identification with Imagined Agents

Background In a previous study, we found that when required to imagine another person performing an action, participants reported a higher correspondence between their own handedness and the hand used by the imagined person when the agent was seen from the back compared to when the agent was seen from the front. This result was explained as evidence of a greater involvement of motor areas in the back-view perspective, possibly indicating a greater proneness to put oneself in the agents shoes in such a condition. In turn, the proneness to put oneself in anothers shoes could also be considered as a cue of greater identification with the other, that is a form of empathy. If this is the case, the proportion of lateral matches vs mismatches should be different for subjects with high and low self-reported empathy. In the present study, we aimed at testing this hypothesis. Methodology/Principal Findings Participants were required to imagine a person performing a single manual action in a back view and to indicate the hand used by the imagined person during movement execution. Consistent with our hypothesis, the proportion of matching between the handedness of participants and the handedness of agents imagined was higher for participants scoring high in a self-report measure of empathy. Importantly, this relationship was specific for females. Conclusions/Significance At least for females, our data seem to corroborate the idea of a link between self-reported empathy and motor identification with imagined agents. This sex-specific result is consistent with neuroimaging studies indicating a stronger involvement of action representations during emotional and empathic processing in females than in males. In sum, our findings underline the possibility of employing behavioral research as a test-bed for theories deriving from functional studies suggesting a link between empathic processing and the activation of motor-related areas.

Running with emotion: When affective content hampers working memory performance

This study tested the hypothesis that affective content may undermine rather than facilitate working memory (WM) performance. To this end, participants performed a running WM task with positive, negative and neutral words. In typical running memory tasks, participants are presented with lists of unpredictable length and are asked to recall the last three or four items. We found that accuracy with affective words decreased as lists lengthened, whereas list length did not influence recall of neutral words. We interpreted this pattern of results in terms of a limited resource model of WM in which valence represents additional information that needs to be manipulated, especially in the context of difficult trials.

Comparing different types of source memory attributes in dementia of Alzheimer's type.

BACKGROUND Source monitoring (SM) refers to our ability to discriminate between memories from different sources. METHODS Twenty healthy high-cognitive functioning older adults, 20 healthy low-cognitive functioning older adults, and 20 older adults with dementia of Alzheimers type (DAT) were asked to perform a series of SM tasks that varied in terms of the to-be-remembered source attribute (perceptual, spatial, temporal, semantic, social, and affective details). RESULTS Results indicated that older DAT adults had greater difficulty in SM compared to the healthy control groups, especially with spatial and semantic details. CONCLUSIONS Data are discussed in terms of the SM framework and suggest that poor memory for some types of source information may be considered as an important indicator of clinical memory function when assessing for the presence and severity of dementia.

When touch matters: An affective tactile intervention for older adults

Aim:  Our goal was to test the hypothesis that positive tactile experiences can lead to an improvement in cognitive, emotional skills and perceived quality of life in a group of healthy community‐dwelling older adults.

Is there an affective working memory deficit in patients with chronic schizophrenia

Research interest in affective working memory has rapidly grown in the last decade. In this study we investigated working memory functions for affective and neutral words in a group of 22 patients with chronic schizophrenia and 22 healthy controls. In particular, participants were administered the operation working memory span task in which affective and neutral words had to be remembered. Results showed that patients made significantly more intrusion errors, recalling off-goal information, and showed poorer long-term memory performance than controls. In addition, affective trials showed the largest number of intrusion errors. These results suggest that a general attentional control deficit, especially over affective information, may underly failures to remember in chronic schizophrenia patients.

Fighting apathy in Alzheimer's dementia: A brief emotional-based intervention

Lack of motivation, or apathy, is a clinically significant feature among dementia patients. The current study aimed to assess the effectiveness of a brief emotional shaping intervention developed to reduce apathy and increase willingness-to-do in Alzheimers Dementia patients. To this end, 26 Alzheimer patients diagnosed with apathy according to the Apathy Evaluation Scale (AES, Marin et al.,1991) and 26 healthy older controls performed an emotional shaping task intended to unconsciously foster willingness-to-do. Participants were randomly assigned to either a positive or a neutral conditioning situation. Results showed how the positively conditioned group was associated with improved willingness-to-do in both patients and controls compared to the neutrally conditioned group. Our findings suggest that unconscious emotional processing can be used to treat apathy symptoms and increase willingness-to-do in Alzheimers Dementia.

Saying it with a natural child's voice! When affective auditory manipulations increase working memory in aging

Objectives: Working memory functions and their relations with affective auditory factors, have not been extensively investigated in aging yet. Method: In this study, younger and older participants completed a classical working memory test (a running working memory task) pronounced by three different voices. In particular, in Experiment 1 the natural voices of a 3-year-old child, a 26-year-old young adult and an 86-year-old older adult were used for task presentation. In Experiment 2 stimuli were morphed in order to better control for sound properties across the three voices. Results: Results showed that working memory increased for older adults compared to younger adults when the task was presented with natural voices and especially so when the task was presented in a childs voice. However, the child-voice effect disappeared with morphed voices. Conclusion: Data confirm the importance of studying the relationship between auditory features and emotional variations as a possible practical means of reducing typical age-related working memory deficits.