Endogenous estradiol is associated with verbal memory in nondemented older men

This study examined the relationship between endogenous hormones and cognitive function in nondemented, ethnically-diverse community-dwelling older men enrolled in the Einstein Aging Study (EAS). All eligible participants (185 men, mean age=81 years) received neuropsychological assessment (Free and Cued Selective Reminding Test (FCSRT), Logical Memory (LM), Trail Making Test B (TMTB), block design (BD)) and provided blood samples for hormonal assays (total estradiol, total testosterone, calculated free testosterone index). Linear regression analysis adjusted for age, education, body mass index, and cardiovascular comorbidities indicated that men with high levels of total estradiol demonstrated better FCSRT verbal memory performance (β=0.17, p<0.02) compared to men with lower levels of total estradiol. The results remained unchanged when the model was further adjusted for ethnicity. We did not detect an association between testosterone and cognitive performance. These findings indicate that high levels of total estradiol in older men are associated with better performance on a cue-based, controlled learning test of verbal memory that is a sensitive predictor of dementia.     

Risk for suicidal ideation and suicide attempts associated with co-occurring depression and conduct problems in early adolescence

This study investigates the early manifestation of co-occurring depression and conduct problems as a predictor of heightened risk for later suicidal ideation and behavior in a community sample of 521 adolescents. Self-reported symptoms of depression and conduct problems were evaluated in early 6th grade. Suicidal thoughts and behaviors were tracked through multiple assessments carried out over the middle school years. Compared to adolescents with depression symptoms only, conduct problem symptoms only, or low psychopathology, those with co-occurring depression and conduct problem symptoms had the highest risk for subsequent suicidal ideation, recurrent suicidal behaviors, and suicide attempts.     

Experience and validity of clinical judgment: The illusory correlation

Mental health experts often justify diagnostic and predictive judgments on the basis of “years of experience” with a particular type of person. Justification by experience is common in legal settings, and can have profound consequences for the person about whom such judgments are made. However, research shows that the validity of clinical judgment and amount of clinical experience are unrelated. The role of experience in learning varies as a function of what is to be learned. Experiments show that learning conceptual categories depends upon: (1) the learner's having clear hypotheses about the possible rule for category membership prior to receiving feedback about which instances belong to the category, and, (2) the systematic nature of such feedback, especially about erroneous categorizations. Since neither of these conditions is satisfied in clinical contexts in psychology, the subsequent failure of experience per se to enhance diagnostic or predictive validity is unsurprising. Claims that “I can tell on the basis of my experience with people of a particular type (e.g., child abusers) that this person is of that type (e.g., a child abuser)” are simply invalid.     

A study of semantic and syntactic processing in monolinguals and fluent early bilinguals

The present study consists of two reaction-time experiments administered in English. These experiments were designed to compare semantic and syntactic processing in English monolinguals and fluent early French-English bilinguals. Results of both experiments revealed that the bilinguals did not function as the English monolinguals did. That is, their reaction times were slower and they made twice as many errors in response to certain sentences. These findings are especially important for two reasons: (1) The bilinguals were all highly fluent, and in most cases dominant, in English, and (2) the bilinguals exhibited systematic differences in two different linguistic components (the semantic and the syntactic). The results are viewed as evidence of the interdependence of the bilinguals' languages. Some note is made of individual patterns of response, and two interpretations of linguistic interdependence are provided.     

The effects of methylphenidate on levels of processing and laterality in children with attention deficit disorder

Effects of stimulant medication (methylphenidate) on levels (feature, name, semantic) of word processing by the left and right hemisphere were assessed in 31 attention- deficit- disordered children. In a double-blind procedure, same- different decisions were made to tachistoscopically presented word pairs under medication and placebo. Analysis of manual response times failed to show any negative effects of medication. Feature decisions were faster than name decisions, which were faster than semantic decisions. Methylphenidate induced a right visual field advantage (left hemisphere) for the name decision, which was interpreted as a normalization effect. The results suggest that (1) methylphenidate may selectively improve the phonological level of word processing and (2) methylphenidate's favorable therapeutic effect is produced through inhibition of excessive right hemisphere activity in response to task demands that engage the left hemisphere.This research is based in part upon a doctoral thesis completed by the first author in the Department of Education, University of Toronto. The authors thank Dr. William Logan and Dr. Wendy Roberts of the Hospital for Sick Children for permitting testing of patients in the Child Development Clinic. This research was supported in part by a doctoral fellowship from the Social Sciences and Humanities Research Council to the first author.     

An adult model of preschool children’s speech memory

In previous work, it has been demonstrated that phonetic similarity among the items in a spoken list interferes with recall much more in school-aged children than in preschool children. The basis of this developmental change, however, is unclear. In the present study we examined the possibility that a developmental increase in the use of covert verbal rehearsal accounts for the change in the effects of phonetic similarity. Adults who recalled lists of spoken words during articulatory suppression tasks that blocked covert rehearsal were found to display patterns of recall that resembled those ordinarily found in 5-year-old children. The specific aspects of rehearsal responsible for these effects also were investigated.