Behavioral and neuronal attributes of short- and long-term habituation in the crab Chasmagnathus

Investigations using invertebrate species have led to a considerable progress in our understanding of the mechanisms underlying learning and memory. In this review we describe the main behavioral and neuronal findings obtained by studying the habituation of the escape response to a visual danger stimulus in the crab Chasmagnathus granulatus. Massed training with brief intertrial intervals lead to a rapid reduction of the escape response that recovers after a short term. Conversely, few trials of spaced training renders a slower escape reduction that endures for many days. As predicted by Wagner’s associative theory of habituation, long-term habituation in the crab proved to be determined by an association between the contextual environment of the training and the unconditioned stimulus. By performing intracellular recordings in the brain of the intact animal at the same time it was learning, we identified a group of neurons that remarkably reflects the short- and long-term behavioral changes. Thus, the visual memory abilities of crabs, their relatively simple and accessible nervous system, and the recording stability that can be achieved with their neurons provide an opportunity for uncovering neurophysiological and molecular events that occur in identifiable neurons during learning.     

Resilience in the Face of Maternal Psychopathology and Adverse Life Events

Maternal psychopathology has long been recognized as a risk factor for psychopathology in offspring; however, some resilient youth achieve a favorable outcome in the presence of maternal psychopathology. We identified factors that predicted resilience among youth who were exposed to adverse life events, and also examined whether the same factors protected youth against maternal psychopathology and adverse life events. Main and interaction effects of child and family factors were examined employing cross-sectional data from a household probability sample of 1285 youth aged 9 through 17 collected at four sites. On average, children exhibited a greater degree of resilience when they had higher IQ, closer parental monitoring, better family functioning, higher educational aspiration, and were female. Interaction between maternal psychopathology and IQ was significant, and there was a trend between maternal psychopathology and gender. A higher IQ is a protective factor against both maternal psychopathology and adverse life events; whereas being a girl seems to be a protective factor against maternal psychopathology, but not adverse life events.     

Mental health status among Puerto Ricans,Mexican Americans,and Non-Hispanic whites

Compared mental health characteristics of island Puerto Ricans to three groups from the Los Angeles Epidemiologic Catchment Area Study: Mexican American immigrants, U.S.-born Mexican Americans, and Non-Hispanic whites. The Diagnostic Interview Schedule was used to obtain both diagnostic and symptom scale information about affective disorders, alcohol abuse/dependence, somatization, phobic disorder, and psychotic disorder. Mexican American immigrants had the fewest mental health problems of all groups. Puerto Ricans had more somatization disorder, but less affective and alcohol disorders than U.S-born Mexican Americans or non-Hispanic whites. Results are considered in the light of selection factors, relative disadvantage of groups and methodological problems. This research was supported by grants MH36230 and MH45763 from the National Institute of Mental Health, and made use of data from the Los Angeles site of the Epidemiologic Catchment Area Program, which is a series of five epidemiologic research studies performed by independent research teams in collaboration with staff of the Division of Biometry and Epidemiology of the National Institute of Mental Health. The NIMH principal collaborators were D. Regier, B. Locke, W. Eaton and J. Burke. The NIMH project officers were C. Taube and W. Huber. The principal investigators and coinvestigators from the five sites were Yale University: J. Myers, M. Weissman, G. Tischler; Johns Hopkins University: M. Kramer, E. Gruenberg, S. Shapiro; Washington University: L. Robins, J. Helzer; Duke University: D. Blazer, L. George; University of California at Los Angeles: M. Karno, R. Hough, J. Escobar, A. Burnam, D. Timbers.     

Parental and family predictors of behavior problems in inner-city black children

Studied contributions of maternal psychological distress, family stress load, maternal and family risk factors, and family coping strategies in predicting behavior problems in 441 inner-city black primary-grade children. Results indicated maternal psychological distress and high family stress load were associated with high child behavior problems. Family coping strategies offered no protection against risk, while coping with life difficulties by reframing them was detrimental to child behavioral adjustment. Active help-seeking strategies (i.e., family mobilization, acquiring social supports) served to moderate the effects of maternal psychological distress and family risk attributes for boys, but exacerbated the effects of dysfunctional maternal social and psychiatric histories for girls. Implications for understanding vulnerability and resilience in inner-city black children and recommendations for future research are discussed.     

Eye remember you two: gaze direction modulates face recognition in a developmental study

The effects of gaze direction on memory for faces were studied in children from three different age groups (6-7, 8-9, and 10-11 years old) using a computerized version of a task devised by Hood, Macrae, Cole-Davies and Dias (2003). Participants were presented with a sequence of faces in an encoding phase, and were then required to judge which faces they had previously encountered in a surprise two-alternative forced-choice recognition test. In one condition, stimulus eye gaze was either direct or deviated at the viewing phase, and eyes were closed at the test phase. In another condition, stimulus eyes were closed at the viewing phase, with either direct or deviated gaze at the test phase. Modulation of gaze direction affected hit rates, with participants demonstrating greater accuracy for direct gaze targets compared to deviated gaze targets in both conditions. Reaction times (RT) to correctly recognized stimuli were faster for direct gaze stimuli at the viewing phase, but not at the test phase. The age group of participants differentially affected these measures: there was a greater hit rate advantage for direct gaze stimuli in older children, although RTs were less affected by age. These findings suggest that while the facilitation of face recognition by gaze direction is robust across encoding and recognition stages, the efficiency of the process is affected by the stage at which gaze is modulated.     

Relation of Age of Onset to the Type and Severity of Child and Adolescent Conduct Problems

In a cross-sectional household sample of 9-through 17-year-old youths from 4 U.S. communities, youths with earlier ages of onset of conduct problems engaged in more conduct problems than youths with later ages of onset when current age and gender were controlled. Specifically, youths with earlier ages of onset were more likely to engage in several types of physical aggression, frequent lying, theft, and vandalism and were less likely to engage in only truancy. There also was an inverse relation between age of onset and level of functional impairment, mental health service use, and meeting diagnostic criteria for conduct disorder, attention-deficit hyperactivity disorder, and oppositional defiant disorder. Within the limits of cross-sectional data, these results support the hypothesis that key aspects of the heterogeneity of conduct problems among youths are related to the age of onset of conduct problems.     

Biased lineups: sequential presentation reduces the problem.

Biased lineups have been shown to increase significantly false, but not correct, identification rates (Lindsay, Wallbridge, & Drennan, 1987; Lindsay & Wells, 1980; Malpass & Devine, 1981). Lindsay and Wells (1985) found that sequential lineup presentation reduced false identification rates, presumably by reducing reliance on relative judgment processes. Five staged-crime experiments were conducted to examine the effect of lineup biases and sequential presentation on eyewitness recognition accuracy. Sequential lineup presentation significantly reduced false identification rates from fair lineups as well as from lineups biased with regard to foil similarity, instructions, or witness attire, and from lineups biased in all of these ways. The results support recommendations that police present lineups sequentially.     

Correlates of suicidal behaviors among Asian American outpatient youths

Medical record abstraction was conducted at an ethnic-specific mental health outpatient clinic to identify correlates of suicidal behaviors in a sample of 285 Asian American youths. Some risk factors, such as parent-child conflict and age, which have been associated with suicidality in majority group youths, predicted suicidality in this sample, whereas other risk factors, such as gender, did not generalize to this sample. Acculturation interacted with the risk factor of parent-child conflict to predict suicidality. Less acculturated Asian youths were at proportionally greater risk for suicidality under conditions of high parent-child conflict than were their more acculturated counterparts. This finding underscores the importance of culture as a context for determining the relevance of stressors for potentiating psychopathology.     

Age of first onset major depression in Chinese Americans

Using data from the Chinese American Epidemiological Study, risk for experiencing an initial episode of major depression across the life course was examined. Data were collected on 1,747 U.S.-born and foreign-born Chinese Americans (ages 18-65 years). Results suggest that Chinese American women did not evidence higher risk than Chinese American men for experiencing a 1st major depressive episode. Risk for experiencing a 1st depressive episode decreased as length of residence in the United States increased. Although those who immigrated at younger ages evidenced greater overall risk, those who came at later ages were more likely to become depressed at or soon after arrival. Competing theories of acculturation-related risk are discussed and directions for future research are proposed.