Experimental Investigation of the Impact of Goal-Oriented Mental Imagery on Reward Perception

Aims: Recent studies have shown that mood can bias perceived reward value, with this effect being strongest in individuals with more mood instability. Spontaneous use of mental imagery has been highlighted as an important feature in generating and maintaining mood symptoms in bipolar disorder. We examined whether mental imagery influencing motivation biases perceived reward value during learning, and to what extent effects are modulated by mood symptoms. Method: 50 healthy participants completed a brief, online-based manipulation in which they generated mental images related to goal-attainment and goal-failure with a view to increasing and decreasing motivation, respectively. We quantified the efficacy of this manipulation on mood and motivation, as well as on the perception of reward stimuli encountered in two learning blocks. Participants performed each block under one of the two types of imagery, thus using a within-participants design. To test for bias in perceived reward value, participants were subsequently asked to indicate their preference in pairwise choices between all stimuli encountered. Trait mood instability (HPS), propensity towards imagery (SUIS), and depression symptoms (PHQ-9) were included in analyses to test for modulatory effects on biased preference. Results: Goal-oriented mental imagery effectively impacted subjective motivation, with higher ratings in the goal-attainment imagery block, compared to goal-failure. Depression symptoms, but not mood instability, were observed to have a modulating effect on change in motivational state. The degree to which momentary motivation was impacted by imagery was positively associated with bias in perceived reward value, and further modulated by depression symptoms. Conclusions: Our findings indicate that goal-oriented mental imagery is effective in impacting motivational state in healthy individuals reporting more depression symptoms, and that motivational state in turn modulates reward perception. Insights are offered to aid development of interventions using mental imagery as an emotional and motivational “amplifier” to improve depressed mood

Necessity of the trade practices

Thesis (M.B.A.)--Boston University, 1935. This item was digitized by the Internet Archive

Economic significance of the automobile

Thesis (M.B.A.)--Boston University, 1930. This item was digitized by the Internet Archive

Sex education in the secondary school

Thesis (M.A.)--Boston University, 1950. This item was digitized by the Internet Archive

Treatment of hypertension in children and adolescents

The treatment of hypertension in children and adolescents has been markedly changed in recent years by several factors, including the publication of new consensus recommendations, the obesity epidemic, and the increased availability of information on efficacy and safety of antihypertensive medications in the young. In this review we present an updated approach to the outpatient management of hypertension in the child or adolescent, utilizing representative cases to illustrate important principles as well as possible controversies

Highly Ionized High-Velocity Clouds toward PKS 2155-304 and Markarian 509

To gain insight into four highly ionized high-velocity clouds (HVCs) discovered by Sembach et al. (1999), we have analyzed data from the Hubble Space Telescope (HST) and Far Ultraviolet Spectroscopic Explorer (FUSE) for the PKS 2155-304 and Mrk 509 sight lines. We measure strong absorption in OVI and column densities of multiple ionization stages of silicon (SiII/III/IV) and carbon (CII/III/IV). We interpret this ionization pattern as a multiphase medium that contains both collisionally ionized and photoionized gas. Toward PKS 2155-304, for HVCs at -140 and -270 km/s, respectively, we measure logN(OVI)=13.80+/-0.03 and log N(OVI)=13.56+/-0.06; from Lyman series absorption, we find log N(HI)=16.37^(+0.22)_(-0.14) and 15.23^(+0.38)_(-0.22). The presence of high-velocity OVI spread over a broad (100 km/s) profile, together with large amounts of low-ionization species, is difficult to reconcile with the low densities, n=5x10^(-6) cm^(-3), in the collisional/photoionization models of Nicastro et al. (2002), although the HVCs show a similar relation in N(SiIV)/N(CIV) versus N(CII)/N(CIV) as high-z intergalactic clouds. Our results suggest that the high-velocity OVI in these absorbers do not necessarily trace the WHIM, but instead may trace HVCs with low total hydrogen column density. We propose that the broad high-velocity OVI absorption arises from shock ionization, at bowshock interfaces produced from infalling clumps of gas with velocity shear. The similar ratios of high ions for HVC Complex C and these highly ionized HVCs suggest a common production mechanism in the Galactic halo.Comment: 38 pages, including 10 figures. ApJ, 10 April, 2004. Replaced with accepted versio