The role of meaning and familiarity in mental transformations

Eighty-four participants mentally rotated meaningful and meaningless objects. Within each type of object, half were simple and half were complex; the complexity was the same across the meaningful and meaningless objects. The patterns of errors were examined as a function of the type of stimuli (meaningful vs. meaningless), complexity, and angle of rotation. The data for the meaningful objects showed steeper slopes of rotation for complex objects than that for simple objects. In contrast, the simple and complex meaningless objects showed comparable increases in error rates as a function of angle of rotation. Furthermore, the slopes remained comparable after pretraining that increased familiarity with the objects. The results are discussed in terms of underlying representations of meaningful and meaningless objects and their implications to mental transformations. The data are consistent with a piecemeal rotation of the meaningful stimuli and a holistic rotation of the meaningless stimuli.     

PET evidence for multiple strategies of categorization

It is widely held that people use multiple strategies to categorize their experiences in the world. We conducted a pair of neuroimaging experiments to identify the neural correlates of two of these strategies— rule application and exemplar similarity. Participants were instructed to perform either a ruleor an exemplar-based categorization task while changes in cerebral blood flow were measured using positron emission tomography. Patterns of neural activity were consistent with the predictions of cognitive models of rule- versus exemplar-based categorization and with existing neuroscience data. The identification of strategy-specific neural patterns offers future researchers a diagnostic tool for assessing strategy use in other situations.     

Investigating the influence of social desirability on personality factor structure

This study provides a comprehensive investigation into whether social desirability alters the factor structure of personality measures. The study brought together 4 large data sets wherein different organizational samples responded to different personality measures. This facilitated conducting 4 separate yet parallel investigations. Within each data set, individuals identified through a social desirability scale as responding in an honest manner were grouped together, and individuals identified as responding in a highly socially desirable manner were grouped together. Using various analyses, the fit of higher order factor structure models was compared across the 2 groups. Results were the same for each data set. Social desirability had little influence on the higher order factor structures that characterized the relationships among the scales of the personality measures.     

Renatus renatus: the Cartesian tradition in British neuroscience and the neurophilosophy of John Carew Eccles

J. C. Eccles (1903-1997) had a highly distinguished career in neurophysiology, being awarded the Nobel Prize for Medicine or Physiology in 1963. This paper sets him within the Cartesian tradition of British neurophysiology initiated by Thomas Henry Huxley in the mid-19th century. It shows how the mind-brain problematique of the Cartesian tradition troubled him throughout his career, leading him finally to a solution in terms of quantum microphysics and microphysiology. This position, which has subsequently become fashionable, is discussed and shown (at least in the form Eccles espoused) to provide no solution to the problem posed by Descartes in the early 17th century.     

Preserved implicit learning on both the serial reaction time task and artificial grammar in patients with Parkinson's disease

Thirteen nondemented patients with Parkinson's disease (PD) were compared with age-matched controls on two standard tests of implicit learning. A verbal version of the Serial Reaction Time (SRT) task was used to assess sequence learning and an artificial grammar (AG) task assessed perceptual learning. It was predicted that PD patients would show implicit learning on the AG task but not the SRT task, as motor sequence learning is thought to be reliant on the basal ganglia, which is damaged in PD. Patients with PD demonstrated implicit learning on both tasks. In light of these unexpected results the research on SRT learning in PD is reconsidered, and some possible explanations for the sometimes conflicting results of PD patient samples on the SRT task are considered. Four factors which merit further study in this regard are the degree to which the SRT task relies on overt motor responses, the effects of frontal lobe dysfunction upon implicit sequence learning, the effects of cerebellar degeneration, and the degree to which the illness itself has advanced.     

Sigmund Koch as critical humanist

Just as Sigmund Koch was a good scientist without succumbing to scientism, he was a good humanist without succumbing to the popular distortions trading on the name of humanism. When humanistic psychology was seduced by the touchy-feely encounter group movement, Koch derided its technology of authenticity as shamelessly meretricious. Later, when postmodern humanists of deconstruction and textual analysis began to be heard in psychology, Koch wryly expressed his preference for the old-fashioned kind of humanism. Koch's interests and his conception of the domain of psychology thus transcended scientific and humanistic labels and boundaries. To be good science, human psychological studies have to start with and be guided by openness to all aspects of being human. No less in the present and future than during his lifetime, the implications of Koch's vision of psychological inquiry warrant discerning and disciplined attention.     

The connubial crucible: newlywed years as predictors of marital delight, distress, and divorce

This study showed that couples' newlywed marriages and changes in their union over the first 2 years foreshadow their long-term marital fate after 13 years. Consistent with the enduring dynamics model, differences in the intensity of newlyweds' romance as well as the extent to which they expressed negative feelings toward each other predicted (a) whether or not they were happy 13 years later (among those who stayed married) and (b) how long their marriage lasted prior to separation (for those who divorced). The results provide little support for the idea that emergence of distress (e.g., increasing negativity) early in marriage leads to marital failure but instead show that disillusionment--as reflected in an abatement of love, a decline in overt affection, a lessening of the conviction that one's spouse is responsive, and an increase in ambivalence--distinguishes couples headed for divorce from those who establish a stable marital bond.     

Effects of LY354740, a novel glutamatergic metabotropic agonist, on nonhuman primate hypothalamic-pituitary-adrenal axis and noradrenergic function

The search for novel anxiolytics and antidepressants has focused on compounds with the potential to reduce excessive hypothalamic-pituitary-adrenal (HPA) axis activity. L-glutamate, an excitatory neurotransmitter ubiquitously present within the central nervous system, conceivably plays an important role in activating the neural sites involved in stress modulation. Deactivation of the HPA axis by glutamatergic neurotransmission modulation may represent a novel therapeutic approach. Accordingly, the acute intravenous effects of the novel metabotropic (mGlu2/3) agonist LY354740 were tested on bonnet macaques (Macaca radiata) undergoing acute infusions of yohimbine, a noradrenergic stimulant. Dependent measures were the magnitude of the increase of plasma cortisol and plasma 3-methoxy-4-hydroxyphenylglycol (MHPG) customarily elicited by yohimbine. Next, the effects of 6 weeks of chronic oral administration of LY354740 on baseline (postcapture) plasma cortisol and MHPG levels in comparison to the identical measure in untreated controls were assessed. Subjects chronically treated with LY354740 received yohimbine infusions which were compared to yohimbine infusions and saline infusions in non-LY354740-treated subjects. Preliminary evidence supports the view that acute LY354740 infusion resulted in a marked diminution of yohimbine-induced stress response, as manifest by a substantial attenuation of cortisol and MHPG response observed in comparison to the saline-treated yohimbine condition. Chronic oral administration of LY354740 led to postcapture baseline cortisol levels which were markedly reduced (approximately 50 percent) in comparison to untreated control subjects; however, there were no significant parallel differences in MHPG levels. Yohimbine infusions elicited an increase in cortisol and MHPG levels in both LY354740-treated and non-LY354740-treated subjects, in comparison to declines in cortisol values observed following vehicle infusions (group X time interaction; P<.0001). Chronic LY354740-treated subjects failed to achieve cortisol levels comparable in range to those of untreated subjects primarily because of their low baseline cortisol levels. In contrast, despite equivalent baselines, yohimbine-induced MHPG values were increased overall in the chronically treated group compared to the saline and yohimbine-alone groups. Thus, LY354740 markedly reduced the acute corticoid and noradrenergic response elicited by yohimbine infusion. Chronic administration of LY354740 appears to present a safe and effective mechanism to markedly down-modulate the HPA axis while retaining noradrenergic responsivity.