Effects of cue focality on the neural mechanisms of prospective memory: A meta-analysis of neuroimaging studies

Remembering to execute pre-defined intentions at the appropriate time in the future is typically referred to as Prospective Memory (PM). Studies of PM showed that distinct cognitive processes underlie the execution of delayed intentions depending on whether the cue associated with such intentions is focal to ongoing activity processing or not (i.e., cue focality). The present activation likelihood estimation (ALE) meta-analysis revealed several differences in brain activity as a function of focality of the PM cue. The retrieval of intention is supported mainly by left anterior prefrontal cortex (Brodmann Area, BA 10) in nonfocal tasks, and by cerebellum and ventral parietal regions in focal tasks. Furthermore, the precuneus showed increased activation during the maintenance phase of intentions compared to the retrieval phase in nonfocal tasks, whereas the inferior parietal lobule showed increased activation during the retrieval of intention compared to maintenance phase in the focal tasks. Finally, the retrieval of intention relies more on the activity in anterior cingulate cortex for nonfocal tasks, and on posterior cingulate cortex for focal tasks. Such focality-related pattern of activations suggests that prospective remembering is mediated mainly by top-down and stimulus-independent processes in nonfocal tasks, whereas by more automatic, bottom-up, processes in focal tasks

Deficit in the Emotional Embodiment in Alexithymia

Alexithymia refers to difficulties in recognizing one’s own emotions and others emotions. Theories of emotional embodiment suggest that, in order to understand other peoples’ feelings, observers re-experience, or simulate, the relevant component (i.e. somatic, motor, visceral) of emotion’s expressed by others in one’s self. In this way, the emotions are “embodied”. Critically, to date, there are no studies investigating the ability of alexithymic individuals in embodying the emotions conveyed by faces. In the present dissertation different implicit paradigms and techniques falling within the field of affective neuroscience have been employed in order to test a possible deficit in the embodiment of emotions in alexithymia while subjects were requested to observe faces manifesting different expression: fear, disgust, happiness and neutral. The level of the perceptual encoding of emotional faces and the embodiment of emotions in the somato-sensory and sensory-motor system have been investigated. Moreover, non-communicative motor reaction to emotional stimuli (i.e. visceral reactions) and interoceptive abilities of alexithymic subjects have been explored. The present dissertation provided convergent evidences in support of a deficit in the processing of fearful expression in subjects with high alexithymic personality traits. Indeed, the pattern of fear induced changes in the perceptual encoding, in the somato-sensory and in the somato-motor system (both the communicative and non communicative one) is widely and consistently altered in alexithymia. This support the hypothesis of a diminished responses to fearful stimuli in alexithymia. In addition, the overall results on happiness and disgust, although preliminary, provided interesting results. Indeed, the results on happiness revealed a defective perceptual encoding, coupled with a slight difficulty (i.e. delayed responses) at the level of the communicative somato-motor system, and the emotion of disgust has been found to be abnormally embodied at the level of the somato-sensory system

What is missing in the study of emotion expression?

While approaching celebrations for the 150 years of “The Expression of the Emotions in Man and Animals”, scientists’ conclusions on emotion expression are still debated. Emotion expression has been traditionally anchored to prototypical and mutually exclusive facial expressions (e.g., anger, disgust, fear, happiness, sadness, and surprise). However, people express emotions in nuanced patterns and – crucially – not everything is in the face. In recent decades considerable work has critiqued this classical view, calling for a more fluid and flexible approach that considers how humans dynamically perform genuine expressions with their bodies in context. A growing body of evidence suggests that each emotional display is a complex, multi-component, motoric event. The human face is never static, but continuously acts and reacts to internal and environmental stimuli, with the coordinated action of muscles throughout the body. Moreover, two anatomically and functionally different neural pathways sub-serve voluntary and involuntary expressions. An interesting implication is that we have distinct and independent pathways for genuine and posed facial expressions, and different combinations may occur across the vertical facial axis. Investigating the time course of these facial blends, which can be controlled consciously only in part, is recently providing a useful operational test for comparing the different predictions of various models on the lateralization of emotions. This concise review will identify shortcomings and new challenges regarding the study of emotion expressions at face, body, and contextual levels, eventually resulting in a theoretical and methodological shift in the study of emotions. We contend that the most feasible solution to address the complex world of emotion expression is defining a completely new and more complete approach to emotional investigation. This approach can potentially lead us to the roots of emotional display, and to the individual mechanisms underlying their expression (i.e., individual emotional signatures)

The guilty brain: the utility of neuroimaging and neurostimulation studies in forensic field

Several studies have aimed to address the natural inability of humankind to detect deception and accurately discriminate lying from truth in the legal context. To date, it has been well established that telling a lie is a complex mental activity. During deception, many functions of higher cognition are involved: the decision to lie, withholding the truth, fabricating the lie, monitoring whether the receiver believes the lie, and, if necessary, adjusting the fabricated story and maintaining a consistent lie. In the previous 15 years, increasing interest in the neuroscience of deception has resulted in new possibilities to investigate and interfere with the ability to lie directly from the brain. Cognitive psychology, as well as neuroimaging and neurostimulation studies, are increasing the possibility that neuroscience will be useful for lie detection. This paper discusses the scientific validity of the literature on neuroimaging and neurostimulation regarding lie detection to understand whether scientific findings in this field have a role in the forensic setting. We considered how lie detection technology may contribute to addressing the detection of deception in the courtroom and discussed the conditions and limits in which these techniques reliably distinguish whether an individual is lying

Alexithymia is related to the need for more emotional intensity to identify static fearful facial expressions

Individuals with high levels of alexithymia, a personality trait marked by difficulties in identifying and describing feelings and an externally oriented style of thinking, appear to require more time to accurately recognize intense emotional facial expressions (EFEs). However, in everyday life, EFEs are displayed at different levels of intensity and individuals with high alexithymia may also need more emotional intensity to identify EFEs. Nevertheless, the impact of alexithymia on the identification of EFEs, which vary in emotional intensity, has largely been neglected. To address this, two experiments were conducted in which participants with low (LA) and high (HA) levels of alexithymia were assessed in their ability to identify static (Experiment 1) and dynamic (Experiment 2) morphed faces ranging from neutral to intense EFEs. Results showed that HA needed more emotional intensity than LA to identify static fearful - but not happy or disgusted - faces. On the contrary, no evidence was found that alexithymia affected the identification of dynamic EFEs. These results extend current literature suggesting that alexithymia is related to the need for more perceptual information to identify static fearful EFEs

Case report: Pragmatic impairment in multiple sclerosis after worsening of clinical symptoms

Pragmatics, defined as the ability to integrate language and context to communicate effectively, may be impaired in Multiple Sclerosis (MS). We present the case of a patient with active secondary progressive MS who, after a first neuropsychological assessment that evidenced only a slight pragmatic impairment, suffered a sudden worsening of her clinical conditions, treated with corticosteroids. After this clinical worsening, her pragmatic abilities declined markedly, both in comprehension and production. This worsening was accompanied by a decline only in one attention task, in the context of an overall stable cognitive functioning. We conclude that pragmatics may be a domain particularly susceptible to cognitive worsening, highlighting the importance of its assessment in clinical practice

When the Single Matters more than the Group (II): Addressing the Problem of High False Positive Rates in Single Case Voxel Based Morphometry Using Non-parametric Statistics

In recent years, an increasing number of studies have used Voxel Based Morphometry (VBM) to compare a single patient with a psychiatric or neurological condition of interest against a group of healthy controls. However, the validity of this approach critically relies on the assumption that the single patient is drawn from a hypothetical population with a normal distribution and variance equal to that of the control group. In a previous investigation, we demonstrated that family-wise false positive error rate (i.e. the proportion of statistical comparisons yielding at least one false positive) in single case VBM are much higher than expected (Scarpazza et al. 2013). Here we examine whether the use of non-parametric statistics, which does not rely on the assumptions of normal distribution and equal variance, would enable the investigation of single subjects with good control of false positive risk. We empirically estimated false positive rates in single case non-parametric VBM, by performing 400 statistical comparisons between a single disease-free individual and a group of 100 disease-free controls. The impact of smoothing (4, 8 and 12 mm) and type of pre-processing (Modulated, Unmodulated) was also examined, as these factors have been found to influence false positive rates in previous investigations using parametric statistics. The 400 statistical comparisons were repeated using two independent, freely available data sets in order to maximize the generalizability of the results. We found that the family-wise error rate was 5% for increases and 3.6% for decreases in one data set; and 5.6% for increases and 6.3% for decreases in the other data set (5% nominal). Further, these results were not dependent on the level of smoothing and modulation. Therefore, the present study provides empirical evidence that single case VBM studies with non-parametric statistics are not susceptible to high false positive rates. The critical implication of this finding is that VBM can be used to characterize neuroanatomical alterations in individual subjects as long as non-parametric statistics are employed

Neuroanatomical abnormalities in first-episode psychosis across independent samples: a multi-centre mega-analysis

Background. Neuroanatomical abnormalities in first-episode psychosis (FEP) tend to be sub tle and widespread. The vast majority of previous studies have used small samples, and there fore may have been underpowered. In addition, most studies have examined participants at a single research site, and therefore the results may be specific to the local sample investigated. Consequently, the findings reported in the existing literature are highly heterogeneous. This study aimed to overcome these issues by testing for neuroanatomical abnormalities in indivi duals with FEP that are expressed consistently across several independent samples. Methods. Structural Magnetic Resonance Imaging data were acquired from a total of 572 FEP and 502 age and gender comparable healthy controls at five sites. Voxel-based morphometry was used to investigate differences in grey matter volume (GMV) between the two groups. Statistical inferences were made at p < 0.05 after family-wise error correction for multiple comparisons. Results. FEP showed a widespread pattern of decreased GMV in fronto-temporal, insular and occipital regions bilaterally; these decreases were not dependent on anti-psychotic medication. The region with the most pronounced decrease – gyrus rectus – was negatively correlated with the severity of positive and negative symptoms. Conclusions. This study identified a consistent pattern of fronto-temporal, insular and occipi tal abnormalities in five independent FEP samples; furthermore, the extent of these alterations is dependent on the severity of symptoms and duration of illness. This provides evidence for reliable neuroanatomical alternations in FEP, expressed above and beyond site-related differ ences in anti-psychotic medication, scanning parameters and recruitment criteri