Anatomically ordered tapping interferes more with one-digit addition than two-digit addition: a dual-task fMRI study

Fingers are used as canonical representations for numbers across cultures. In previous imaging studies, it was shown that arithmetic processing activates neural resources that are known to participate in finger movements. Additionally, in one dual-task study, it was shown that anatomically ordered finger tapping disrupts addition and subtraction more than multiplication, possibly due to a long-lasting effect of early finger counting experiences on the neural correlates and organization of addition and subtraction processes. How arithmetic task difficulty and tapping complexity affect the concurrent performance is still unclear. If early finger counting experiences have bearing on the neural correlates of arithmetic in adults, then one would expect anatomically and non-anatomically ordered tapping to have different interference effects, given that finger counting is usually anatomically ordered. To unravel these issues, we studied how (1) arithmetic task difficulty and (2) the complexity of the finger tapping sequence (anatomical vs. non-anatomical ordering) affect concurrent performance and use of key neural circuits using a mixed block/event-related dual-task fMRI design with adult participants. The results suggest that complexity of the tapping sequence modulates interference on addition, and that one-digit addition (fact retrieval), compared to two-digit addition (calculation), is more affected from anatomically ordered tapping. The region-of-interest analysis showed higher left angular gyrus BOLD response for one-digit compared to two-digit addition, and in no-tapping conditions than dual tapping conditions. The results support a specific association between addition fact retrieval and anatomically ordered finger movements in adults, possibly due to finger counting strategies that deploy anatomically ordered finger movements early in the development.     

Impulsivity in adults: motor inhibition and time-interval estimation

There is a need for the development of behavioral measures of impusivity in order to elucidate the specific qualities of impulsive persons. The relationships between two behavioral measures of impulsivity and several personality inventories frequently used to assess inpulsivity were examined using 40 male Ss. The behavioral measures involved a motor-inhibition (MI) task and time-interval (TI) estimation. The personality measures included the Extraversion (E), Psychoticism (P) and Neuroticism (N) scales of the Eysenck Personality Questionnaire (EPQ), Barrat's Impulsivity Scale (BIS) and Gough's Socialization Scale (So). Significant relationships between MI scores and E, BIS and a proposed dimension of impulsivity obtained by the formation of E-P quadrants were found. In addition, performance on this task was related to So, P and E-N quadrants in the predicted directions. The consistency of these results supports the use of this task as a behavioral measure of impusivity in adults. Although personality inventory scores were not related to estimations, significant (negative) correlations were obtained between TI estimations and MI scores. The results indicate that TI estimation by itself is not an adequate measure of impulsivity, but does have implications for understanding impulsive behavior.     

The super-ordinate nature of the psychopathy checklist-revised

Psychopathy, while perhaps the earliest and most recognized personality disorder, is the subject of intense debate about its nature and measurement. The most recent proposal on its structural nature suggests that it is a multifaceted construct, made up of at least four dimensions reflecting Interpersonal, Affective, Lifestyle, and Antisocial anomalies (Hare & Neumann, 2005, 2006). These dimensions are significantly interrelated, suggesting that they are indicators for a super-ordinate factor. The nature of this higher-order factor may reflect the unifying feature which comprehensively defines the disorder. To examine this super-factor, the current study used several very large data sets of male (N = 4865) and female (N = 1099) offenders, and forensic psychiatric patients (N = 965), who were assessed with the Psychopathy Checklist-Revised (PCL-R; Hare, 2003). Structural equation modeling results indicated that the four first-order factor dimensions could be explained by a single second-order cohesive super-factor.     

Anxiety moderates the interplay between cognitive and affective processing

Evidence suggests that focus of attention and cognitive load may each affect emotional processing and that individual differences in anxiety moderate such effects. We examined (a) fear-potentiated startle (FPS) under threat-focused (TF), low-load/alternative-set (LL/AS), and high-load/alternative-set (HL/AS) conditions and (b) the moderating effect of trait anxiety on FPS across these conditions. As predicted, redirecting attentional focus away from threat cues and increasing cognitive load reduced FPS. However, the moderating effects of anxiety were specific to the LL/AS condition. Whereas FPS was comparable for high-anxiety and low-anxiety subjects in the TF and HL/AS conditions, FPS was significantly greater for high-anxiety than for low-anxiety subjects in the LL/AS condition. These results suggest that affective processing requires attentional resources and that exaggerated threat processing in anxious individuals relates to direction of attention rather than emotional reactivity per se.     

Learning your way around town: how virtual taxicab drivers learn to use both layout and landmark information

By having subjects drive a virtual taxicab through a computer-rendered town, we examined how landmark and layout information interact during spatial navigation. Subject-drivers searched for passengers, and then attempted to take the most efficient route to the requested destinations (one of several target stores). Experiment 1 demonstrated that subjects rapidly learn to find direct paths from random pickup locations to target stores. Experiment 2 varied the degree to which landmark and layout cues were preserved across two successively learned towns. When spatial layout was preserved, transfer was low if only target stores were altered, and high if both target stores and surrounding buildings were altered, even though in the latter case all local views were changed. This suggests that subjects can rapidly acquire a survey representation based on the spatial layout of the town and independent of local views, but that subjects will rely on local views when present, and are harmed when associations between previously learned landmarks are disrupted. We propose that spatial navigation reflects a hierarchical system in which either layout or landmark information is sufficient for orienting and wayfinding; however, when these types of cues conflict, landmarks are preferentially used.     

Narcissism and Cardiovascular Reactivity to Rejection Imagery1

This study examined the interactive effects of imagined rejection and narcissism on cardiovascular reactivity (CVR). Participants completed measures of overt narcissism (Narcissistic Personality Inventory, NPI; Raskin & Hall, 1979 ), overt–covert narcissism ( Margolis & Thomas, 1980 ), and trait self‐esteem. They then imagined 2 scenarios culminating in either interpersonal acceptance or rejection. Systolic (SBP) and diastolic blood pressure (DBP) and heart rate (HR) were assessed before, during, and after the imagery. Overt–covert narcissism was positively associated with task increases in SBP and DBP and recovery elevation of HR following rejection, but not acceptance. Similar effects on SBP were found for the Entitlement/Exploitativeness dimension of the NPI. Lower self‐esteem predicted greater task increases in SBP, DBP, and HR across conditions. Implications for health are discussed.     

Development and initial reliability and validity of a new measure of distorted maternal representations: The Mother–Infant Relationship Scale

Distorted maternal representations (DMRs)—mother's ideas, understanding, and feelings about the infant—shape early interaction and the emerging relationship. Distorted interactions reportedly affect infant attachment and socioemotional development and may be associated with maternal early adversity and trauma. Limited measures are available that could be used as screening tools of DMRs. The aims of this study were to (a) describe the development of the Mother–Infant Relationship Scale (MIRS) and (b) to evaluate its psychometric properties. The development and validation of the MIRS closely followed standard guidelines for the development of psychometric tests. Psychometric properties were examined across two samples: 78 adult psychiatric patients with features of borderline personality and 86 individuals from a nonclinical sample (N = 164). The scale demonstrated excellent internal consistency (Cronbach's α = .91) for the clinical sample and adequate internal consistency (.78) for the nonclinical sample, excellent test-retest reliability (intraclass correlation coefficient = .81), and good concurrent validity with an observational (Pearson's correlation coefficients = −.35 to −.54) and a representational measure (.53). Factor analysis revealed three components: DMRs specific to (a) maternal hostility/rejection of the infant, (b) issues about parenting/attachment, and (c) anxiety/helplessness about infant care. Findings suggest that the MIRS is a reliable and valid screening tool of DMRs. Potential uses in clinical and research settings are discussed.