Generating animal and tool names: an fMRI study of effective connectivity

The present fMRI study of semantic fluency for animal and tool names provides further evidence for category-specific brain activations, and reports task-related changes in effective connectivity among defined cerebral regions. Two partially segregated systems of functional integration were highlighted: the tool condition was associated with an enhancement of connectivity within left hemispheric regions, including the inferior prefrontal and premotor cortex, the inferior parietal lobule and the temporo-occipital junction; the animal condition was associated with greater coupling among left visual associative regions. These category-specific functional differences extend the evidence for anatomical specialization to lexical search tasks, and provide for the first time evidence of category-specific patterns of functional integration in word-retrieval.     

The control of responsiveness in ADHD by catecholamines: evidence for dopaminergic, noradrenergic and interactive roles

We explore the neurobiological bases of attention deficit hyperactivity disorder (ADHD) from the viewpoint of the neurochemistry and psychopharmacology of the catecholamine-based behavioural systems. The contributions of dopamine (DA) and noradrenaline (NA) neurotransmission to the motor and cognitive symptoms of ADHD (e.g. hyperactivity, variable and impulsive responses) are studied in rodent and primate models. These models represent elements of the behavioural units observed in subjects with ADHD clinically, or in laboratory settings (e.g. locomotion, changed sensitivity/responsivity to novelty/reinforcement and measures of executive processing). In particular, the models selected emphasize traits that are strongly influenced by mesocorticolimbic DA in the spontaneously hypertensive (SHR) and the Naples high excitability (NHE) rat lines. In this context, the mode of action of methylphenidate treatment is discussed. We also describe current views on the altered control by mesolimbic catecholamines of appropriate and inappropriate goal-directed behaviour, and the tolerance or intolerance of delayed reinforcement in ADHD children and animal models. Recent insights into the previously underestimated role of the NA system in the control of mesocortical DA function, and the frontal role in processing information are elaborated.     

The attentional cost of inattentional blindness

When our attention is engaged in a visual task, we can be blind to events which would otherwise not be missed. In three experiments, 97 out of the 165 observers performing a visual attention task failed to notice an unexpected, irrelevant object moving across the display. Surprisingly, this object significantly lowered accuracy in the primary task when, and only when, it failed to reach awareness. We suggest that an unexpected stimulus causes a state of alert that would normally generate an attentional shift; if this response is prevented by an attention-consuming task, a portion of the attentional resources remains allocated to the object. Such a portion is large enough to disturb performance, but not so large that the object can be recognized as task-irrelevant and accordingly ignored. Our findings have one counterintuitive implication: irrelevant stimuli might hamper some types of performance only when perceived subliminally.     

Reward anticipation enhances brain activation during response inhibition

The chance to achieve a reward starts up the required neurobehavioral mechanisms to adapt our thoughts and actions in order to accomplish our objective. However, reward does not equally reinforce everybody but depends on interindividual motivational dispositions. Thus, immediate reward contingencies can modulate the cognitive process required for goal achievement, while individual differences in personality can affect this modulation. We aimed to test the interaction between inhibition-related brain response and motivational processing in a stop signal task by reward anticipation and whether individual differences in sensitivity to reward (SR) modulate such interaction. We analyzed the cognitive–motivational interaction between the brain pattern activation of the regions involved in correct and incorrect response inhibition and the association between such brain activations and SR scores. We also analyzed the behavioral effects of reward on both reaction times for the “go” trials before and after correct and incorrect inhibition in order to test error prediction performance and postinhibition adjustment. Our results show enhanced activation during response inhibition under reward contingencies in frontal, parietal, and subcortical areas. Moreover, activation of the right insula and the left putamen positively correlates with the SR scores. Finally, the possibility of reward outcome affects not only response inhibition performance (e.g., reducing stop signal reaction time), but also error prediction performance and postinhibition adjustment. Therefore, reward contingencies improve behavioral performance and enhance brain activation during response inhibition, and SR is related to brain activation. Our results suggest the conditions and factors that subserve cognitive control strategies in cognitive motivational interactions during response inhibition.     

The measurement of left—right asymmetries in the Simon effect: A fine-grained analysis

The spatial Simon effect is often asymmetric, being greater on one side than on the other. To date, not much attention has been paid to these asymmetries, and explanations of the Simon effect do not take them into account. In the present article, we attempt to clarify the statistical implications of the asymmetries so as to provide a useful tool for future empirical investigation. Starting with examples from our laboratory and previous well-known studies, we point out the consequences of ignoring the asymmetries in the Simon effect. We suggest an alternative data analysis that might render the results clearer. Finally, through a comparison of left- and right-handed subjects, we demonstrate that asymmetries in the Simon effect are linked to the lateralization of processes involved in the Simon task—that is, attention and response selection. This approach provides a strong argument against collapsing data from the two sides to measure the Simon effect.     

Knowing about not remembering: developmental dissociations in lack‐of‐memory monitoring

Children aged 7 and younger encounter great difficulty in assessing whether lack of memory for an event indicates that the event was not experienced. The present research investigated whether this difficulty results from a general inability to evaluate memory absence or from a specific inability to monitor one feature of memory absence that has been examined in previous studies, namely expected memorability. Seven‐, 8‐ and 9‐year‐olds, and adults (N = 72) enacted, imagined and confabulated about bizarre and common actions. Two weeks later, participants were asked to recognize the actions that had been enacted. Even 7‐year‐olds monitored the relative familiarity of rejected distracters (i.e. reported higher confidence for the rejection of novel versus imagined and confabulated distracters). However, only older children and adults exhibited the ability to monitor expected memorability (e.g. reported higher confidence for the rejection of bizarre versus common distracters). These results suggest that young children exhibit specific, rather than general, deficits in monitoring memory absence, and provide an indication of the specific domains in which lack‐of‐memory monitoring improves during childhood.     

The indirect effect of cognitive reserve on the relationship between age and cognition in pathological ageing: A cross-sectional retrospective study in an unselected and consecutively enrolled sample

Cognitive reserve (CR) allows individuals to maintain cognitive functionality even in the presence of pathologies. The compensation hypothesis suggests that CR plays an indirect role between age and cognitive decline, contrasting the negative effect of ageing on cognition. We test this hypothesis in an unselected and consecutively enrolled sample of memory clinic attendees (n = 134) who completed the CR Index questionnaire and three neuropsychological tests assessing global cognition (MMSE, FAB, CDT). Participants were divided into two groups based on standard diagnostic criteria (DSM-5): those who were cognitively impaired (n = 92) and those who were preserved (n = 42). A principal component analysis was used to extract a composite measure of global cognitive functioning from the three neuropsychological tests, and mediation analysis was used to examine the relationship between CR, age and global cognitive functioning in the two groups. Results revealed that: (i) age had a significant direct negative effect on the global cognitive score in both groups; (ii) the three socio-behavioural proxies of CR together suppress the direct negative relationship between age and global cognitive score in cognitively impaired patients but not in cognitively preserved participants. This study confirms the association between CR, age and cognition and allows us to validate its role in a population with cognitive impairment and extend findings to a low-to-middle educated population. These results hold important implications for public health and wellness promotion, emphasising the beneficial role of maintaining healthy and active physical, cognitive and social lifestyles.     

Adult attachment styles and psychological disease: examining the mediating role of personality traits

The aim of the present study was to examine differences in anxiety and depression related to differences in attachment models of the self and of others and whether personality traits mediate this relationship. The authors assessed attachment styles, anxiety, depression, and personality traits among 274 adult volunteers. Participants were classified into 4 attachment groups (secure, preoccupied, fearful, and dismissing-avoidant) according to K. Bartholomew's (1990) model. The present authors found significant differences among attachment groups on anxiety and depressive symptoms with attachment styles involving a negative self-model showing higher scores than attachment styles characterized by a positive self-model. The authors also found that differences between attachment styles in anxiety and depression remained significant when personality factors related to attachment prototypes were entered as covariates. Results indicate that secure attachment in adults was associated with better mental health, while insecure attachment styles characterized by negative thinking about the self were associated with higher depression and anxiety scores. Our findings seem to evidence that attachment and personality are only partly overlapping and that attachment cannot be considered as redundant with personality in the explanation of psychological disease.     

Emotion regulation strategies in preschool children

This study investigated the development of emotion regulation strategies as reflected in the narratives of children between the ages of 3 and 6 years. An experimental procedure based on story completion tasks was devised to elicit the emotion‐related narratives of 69 preschool children. Coding of the narratives led to the observation of different emotion regulation strategies: Behavioural strategies, social support, and cognitive reappraisal. Several significant gender and age differences were identified in the use of these strategies. In addition, verbal skills, non‐verbal intelligence, and emotion comprehension were found to be associated with use of the observed emotion regulation strategies, although only at specific ages.