On pacing trials while scanning brain hemodynamics: The case of the SNARC effect

Psychonomic Bulletin & Review - Experimental designs used to describe psychological effects on overt human behavior are seldom suited to localize their corresponding neural substrates based on...     

Transcranial Direct Current Stimulation of the Left Temporal Lobe Modulates Insight

Creativity is the ability to come up with new and original solutions to problems. It is characterized along a dipole spectrum, with the opposing ends defined as convergent and divergent thinking. Previous studies have provided evidence that various cognitive functions and insight into non-verbal problems can be enhanced using non-invasive brain stimulation. The aim of this pilot study was to investigate whether convergent and divergent thinking, as well as insight, can be modulated by transcranial direct current stimulation (tDCS) over the anterior temporal lobe (ATL). Bilateral tDCS (1.5 mA, 20 minutes) was used to modulate activity of the right (AR tDCS) and the left (AL tDCS) ATL. Twenty-one participants performed a divergent thinking test (DTT) during tDCS, while a Remote Associates Task (RAT) was administered before and after tDCS to assess convergent thinking. A control experiment, using a Simple Reaction Time (SRT) Task, was conducted in 10 subjects before and after ATL tDCS in order to investigate whether its effects reflect attention or motor effects on the dominant hand. Results from this preliminary study showed that AL tDCS reduced RAT reaction times (RTs) by 20%. Both AL and AR tDCS did not change RAT accuracy, or the DTT total or sub-item scores. No differences were found in the SRT task after either AL or AR tDCS. These findings suggest that left but not right ATL is involved in convergent thinking. Conversely, both left and right temporal cortex tDCS-induced excitability changes failed to modulate divergent thinking. Limitations are discussed.     

Category Cued Recall Following Controlled Encoding as a Neuropsychological Tool in the Diagnosis of Alzheimer’s Disease: A Review of the Evidence

Aim of the present review paper was to evaluate the hypothesis (included in the proposal of new research criteria for Alzheimer’s disease; Dubois et al., Lancet Neurology, 6, 734–746, 2007) that a neuropsychological tool which provides support for the semantic encoding of memorandum at the time of study and supplies category cues at the time of retrieval (i.e. the Grober-Buschke paradigm) is more effective than traditional measures of free recall in 1) differentiating patients affected by the amnestic form of Mild Cognitive Impairment (MCI) or by mild to moderate forms of Alzheimer’s disease (AD) from healthy matches, 2) predicting the conversion of individuals with MCI to AD, and 3) differentiating AD patients from individuals affected by other forms of dementia. Results of the review are controversial regarding the superiority of the Grober-Buschke procedure in differentiating individuals affected by AD or MCI from healthy individuals. The only study that evaluated this issue directly found that the Grober-Buschke procedure was more sensitive and specific than more traditional memory tests in predicting the conversion of MCI patients to AD. Finally, two studies reported that patients affected by AD or other forms of dementia showed different performance patterns in the free and cued recall tasks of the Grober-Buschke procedure. In conclusion, although encouraging results are reported in the few studies that investigated the ability of this procedure to predict the evolution of individuals with amnestic MCI and to differentiate AD patients from patients with other forms of cortical and subcortical dementia, more experimental work is needed to confirm these positive findings.     

Hallucinations and REM sleep behaviour disorder in Parkinson's disease: dream imagery intrusions and other hypotheses

REM sleep behaviour disorder (RBD) is a REM sleep-related parasomnia which may be considered a “dissociated state of wakefulness and sleep”, given that conflicting elements of REM sleep (dreaming) and of wakefulness (sustained muscle tone and movements) coexist during the episodes, leading to motor and behavioural manifestations reminiscent of an enacted dream. RBD has been reported in association with α-synucleinopathies: around a third of patients with Parkinson’s disease (PD) have full-blown RBD.Recent data indicate that PD patients with RBD are more prone to hallucinations than PD patients without this parasomnia. However it is still not clear why RBD in PD is associated with an increased prevalence of VHs.Data exist which suggest that visual hallucinations in PD may be the result of untimely intrusions of REM visual imagery into wakefulness. RBD, which is characterised by a REM sleep dissociation pattern, might be a condition that particularly favours such intrusions. However, other hypotheses may be advanced. In fact, deficits in attentional, executive, visuoperceptual and visuospatial abilities have been documented in RBD and found to occur far more frequently in PD with RBD than in PD without RBD. Neuropsychological deficits involving visual perception and attentional processes are thought to play an important role in the pathophysiology of VHs. On this basis, RBD in PD could be viewed as a contributory risk factor for VHs.     

Personality Foundations of Ideological Divide: A Comparison of Women Members of Parliament and Women Voters in Italy

Empirical research is crucial for understanding the personality foundations of political preferences in modern democracies. However, few studies have addressed the personality of top politicians using standard methods to assess basic traits and personal values. In the current research, traits and values of 106 female members of the Italian Parliament were assessed in accordance with the Five‐Factor Model of personality and Schwartz's taxonomy. The same variables were measured in a sample of 864 voters taken from the general population. We investigate the extent to which differences in traits and values contribute to ideological orientation of politicians and voters of rival coalitions. A similar pattern of relations was found in both groups. Yet, traits and values contributed to partisanship of politicians much more than to political preferences of voters. Whereas values fully mediated the contribution of traits to voting, energy/extraversion and agreeableness contributed to political partisanship both directly and indirectly, through values.     

Neuropsychological Performance in Gulf War Era Veterans: Neuropsychological Symptom Reporting

Relationships between broad-based health symptoms and neuropsychological performance have been investigated previously in Gulf War (GW) veterans. However, very little has been done to assess relationships between severity of neuropsychological symptom complaints and performance on objective neuropsychological tests. In this study, relationships between level of self-reported neuropsychological symptom severity and objective neuropsychological performance measures were investigated. Participants included 240 veterans from three GW-era cohorts: GW-deployed veterans recruited from Ft. Devens, MA, (n = 142) and from New Orleans, LA (n = 51), and veterans deployed to Germany from a Maine National Guard unit (n = 47). Findings suggest that level of subjective neuropsychological complaints was associated primarily with mood symptoms in GW-era veterans. Among GW-deployed troops, high neuropsychological symptom reporters endorsed more tension, fatigue, and confusion and less vigor than those reporting fewer cognitive complaints. Current findings emphasize the importance of independent assessment of subjective symptoms and objective neuropsychological performance.     

Preschoolers' and adults' attributions of who causes interpersonal events

Adults and 4‐year‐olds explained who caused prosocial or antisocial interactions between two characters who differed in two dimensions that underlie interpersonal traits. Participants saw pictures depicting every pairwise combination of four characters (good/powerful, good/weak, bad/powerful or bad/weak) as initiators or recipients of six actions. Both children and adults made causal attributions to ‘good’ characters for prosocial behaviours and to ‘bad’ characters for antisocial behaviours. Potency influenced the frequency of attributions. Adults and children differed in the justifications of their attributions and in their reconciliations of contradictory information, e.g. a positive character initiating an antisocial act. Explanations of social events are based on characteristics of both interactants in combination with whether the event is prosocial or antisocial. The findings thus extend work on children's ‘theory‐of‐mind’ to the realm of interpersonal interactions, where beliefs, desires or dispositions of either of two characters can cause an event. Copyright © 2003 John Wiley & Sons, Ltd.