The Seattle Longitudinal Study: Relationship Between Personality and Cognition

This article reviews the history, measures and principal findings of the Seattle Longitudinal Study. This study began in 1956 focusing upon age differences and age changes in cognitive abilities. Its sampling frame is a large HMO in the Pacific Northwest. The study has been expanded to investigate various influences on cognitive aging including, cognitive styles, personality traits, life styles, and family environment. Current interest is also in the early detection of risk for dementia. In addition, this article reports original analyses of the relation of personality dimensions to cognitive abilities (both concurrent and longitudinal). While personality remains relatively stable over the adult life span, modest proportions of variance are shared between various personality traits and the cognitive abilities.     

Sex-role stereotyping,the motive to avoid success,and parental identification

Fifth- and tenth-grade girls were compared with respect to three sex-role-related variables: sex-role stereotyping; the motive to avoid success; and one aspect of identification motivation — the desire to emulate the father versus the mother. These variables were seen as reflecting certain conflicts and problems associated with feminine sex-role socialization. Age-related increases in stereotyping, the incidence of fear of success, and desire to emulate the father rather than the mother were expected. The motive to avoid success was expected to be associated with low stereotyping and with rejection of the maternal model. In the results, significant increases with age were found in stereotyping and father preference. The expected correlates of the motive to avoid success were found, but in each case for only one of the two age levels. Findings were discussed in relation to difficulties associated with feminine development.     

Does the context of reinforcement affect resistance to change?

Eight pigeons were trained on multiple schedules of reinforcement where pairs of components alternated in blocks on different keys to define 2 local contexts. On 1 key, components arranged 160 and 40 reinforcers/hr; on the other, components arranged 40 and 10 reinforcers/hr. Response rates in the 40/hr component were higher in the latter pair. Within pairs, resistance to prefeeding and resistance to extinction were generally greater in the richer component. The two 40/hr components did not differ in resistance to prefeeding, but the 40/hr component that alternated with 10/hr was more resistant to extinction. This discrepancy was interpreted by an algebraic model relating response strength to component reinforcer rate, including generalization decrement. According to this model, strength is independent of context, consistent with research on schedule preference.     

Validation of the Preschool Anxiety Scale-Traditional Chinese (PAS-TC) in Hong Kong

Anxiety disorders are the most common type of psychiatric conditions in children. Early identification and intervention during preschool years is critical for minimizing their detrimental long-term effects. The Preschool Anxiety Scale (PAS) is a developmentally-sensitive and symptom-specific instrument that has been commonly used and widely validated in the west. The current study tested the psychometric properties of its Traditional Chinese version (PAS-TC) in Hong Kong. The study sample consisted of a total of 1317 Hong Kong parents, recruited from 12 local preschools, with preschool children aged from three to six years old. Results showed that a correlated five-factor model demonstrated a good fit for the data. PAS-TC also demonstrated acceptable reliability and satisfactory validity. Furthermore, gender but not age effects were found in Hong Kong. Additionally, similar to previous studies, items from physical injury fears were the most reported in the top-ten frequently endorsed items. Finally, the anxiety level of our Hong Kong sample was found to be between the Mainland China and western countries. Clinical implications of the above findings concerning PAS-TC are discussed.

     

Enhanced neuronal excitability in rat CA1 pyramidal neurons following trace eyeblink conditioning acquisition is not due to alterations in I M

Previous work done by our laboratory has demonstrated a reduction of the post-burst afterhyperpolarization (AHP) and accommodation following trace eyeblink conditioning in rabbit CA1 pyramidal neurons. Our laboratory has also demonstrated a reduction in the AHP in rat CA1 pyramidal neurons following spatial learning. In the current study we have extended our findings in rabbits by showing a reduction in both the AHP and accommodation in F344 X BN rat CA1 pyramidal neurons following acquisition of trace eyeblink conditioning. A component current of the AHP, I(M), was evaluated with a specific blocker of this current, and showed no apparent contribution to the learning-related increase in neuronal excitability. Rather, a reduction in an isoproterenol-sensitive component of the AHP, presumably sI(AHP), was observed to underlie the learning-specific change.     

Counting Chicks Before They Hatch: Female Cowbirds Can Time Readiness of a Host Nest for Parasitism

ABSTRACT— Here we show that demands associated with brood parasitism have favored sophisticated cognitive abilities in female brown-headed cowbirds. We discovered that cowbirds can use the rate at which eggs are added to a nest across days to assess the readiness of the nest for incubation, which would allow them to synchronize laying with the host and avoid nests where incubation has most likely commenced. In three experiments, cowbirds investigated and laid eggs in artificial nests that differed in the number of eggs they contained. Across days, we added eggs to nests at different rates to simulate differences in the timing of reproduction of the hosts. Cowbirds avoided a nest if the number of eggs that had been added was less than the number of days that had elapsed. The ability of females to remember egg number and compare changes in egg number across days allows them to select nests most suitable for parasitism.     

Developmental origins of sociality in brown-headed cowbirds (Molothrus ater)

Five variables were studied relating to the emergence of sociality in hand-reared cowbirds (Molothrus ater): proximity, sex assortment, reactions to adults, head-down displays, and vocalizations. The authors were especially interested in female sociality because adult female birds influence male courtship, song content, and use through proximity, attention, and displays. The authors found that young female birds failed to show same-sex affiliation typical of the species at any point in the study. Brief introduction of adults did not affect social patterns. Adults used more head-down displays than juveniles, who used more displays with familiar peers. Directed and undirected singing emerged concurrently; directed singing was positively correlated with earlier hatching. This is the first demonstration of the need for early learning in the development of female sociality.     

Simultaneous training on two hippocampus-dependent tasks facilitates acquisition of trace eyeblink conditioning

A common cellular alteration, reduced post-burst afterhyperpolarization (AHP) in CA1 neurons, is associated with acquisition of the hippocampus-dependent tasks trace eyeblink conditioning and the Morris water maze. As a similar increase in excitability is correlated with these two learning paradigms, we sought to determine the interactive behavioral effects of training animals on both tasks by using either a consecutive or simultaneous training design. In the consecutive design, animals were trained first on either the trace eyeblink conditioning task for six sessions, followed by training on the water maze task for six sessions, or vice versa. The simultaneous design consisted of six or 11 training days; animals received one session/day of both trace eyeblink conditioning and water maze training. Separate groups were used for consecutive and simultaneous training. Animals trained on both tasks simultaneously were significantly facilitated in their ability to acquire the trace eyeblink conditioning task; no effect of simultaneous training was seen on the water maze task. No effect was seen on acquisition for either task when using the consecutive training design. Taken together, these findings provide insight into how the hippocampus processes information when animals learn multiple hippocampus-dependent tasks.     

The Comorbidity of Post-traumatic Stress Disorder and Suicidality in Vietnam Veterans

Vietnam veterans (N = 232) recruited from three sources were assessed for suicidal thinking and behaviors, and symptoms of posttraumatic stress disorder (PTSD) and depression. Findings support the notion that suicidal thoughts are prevalent in this group, with veterans in psychotherapy reporting a greater likelihood of such symptoms (82.6%) than veterans in the community (35.7%) or those seeking assistance through a veteran's outreach center (66.7%). Thoughts of ending one's life and a previous suicide attempt were significantly correlated with a diagnosis of PTSD (r = .53, p < .001; and r = .33, p < .001, respectively). Veterans with a diagnosis of PTSD and depression or dysthymia were also more likely to report suicidal thinking and behaviors than veterans with only one of the diagnoses.