Exploring the mental health of Mexican migrant farm workers in the Midwest: psychosocial predictors of psychological distress and suggestions for prevention and treatment

The purposes of the present study were threefold: (a) to assess the prevalence levels of anxiety and depression in a sample of Mexican migrant farm workers in the midwestern United States; (b) to explore the relationships among acculturative stress, anxiety, and depression; and (c) to examine the variables that best predict anxiety and depression. The overall sample revealed elevated levels of anxiety and depression. Migrant farm workers with heightened levels of acculturative stress were more likely to report high levels of anxiety and depression. Family dysfunction, ineffective social support, low self-esteem, lack of agreement with the decision to migrate, high education levels, high levels of acculturative stress, and high levels of anxiety were significantly associated with high depression levels. The overall findings suggest that migrant farm workers who experience elevated levels of acculturative stress may be at risk for experiencing high levels of anxiety and depression. The findings highlight the importance of establishing prevention and treatment services for migrant farm workers that aim to increase levels of emotional support, self-esteem, and coping skills.     

Unrealistic optimism and perceived control: role of personal competence

This work analyzed the effects of unrealistic optimism in the interaction between the emotional valence of future events, the perception of control over these events, and the person with whom one compares oneself. It was hypothesized that, if the person of comparison is judged as very competent, a pessimistic bias should be produced. Likelihood of four different types of events (positive and controllable, positive and uncontrollable, negative and controllable, and negative and uncontrollable) were rated by 133 university students (22 men and 111 women) for themselves, for an average student, for their best friend, and for a bright friend. A pessimistic bias was observed on the relative likelihood of the events when the comparison was made between oneself and a competent and bright friend, when events were perceived as controllable, especially positive ones. Not enough is known, however, to provide meaningful interpretation at present; that must await further data and theoretical development.     

Satisfiability Testing for Boolean Formulas Using Δ-trees

The tree-based data structure of -tree for propositional formulas is introduced in an improved and optimised form. The -trees allow a compact representation for negation normal forms as well as for a number of reduction strategies in order to consider only those occurrences of literals which are relevant for the satisfiability of the input formula. These reduction strategies are divided into two subsets (meaning- and satisfiability-preserving transformations) and can be used to decrease the size of a negation normal form A at (at most) quadratic cost. The reduction strategies are aimed at decreasing the number of required branchings and, therefore, these strategies allow to limit the size of the search space for the SAT problem.     

Sleep-dependent hippocampal slow activity correlates with waking memory performance in humans

The positive effect of postlearning sleep on memory consolidation as well as the relationship between sleep-related memory processes and the hippocampal formation are increasingly clarified topics in neurobiology. However, the possibility of a stable relationship between waking mnemonic performance and sleep-dependent hippocampal electric activity is unexplored. Here we report a correlative analysis between sleep-dependent parahippocampal-hippocampal (pHip-Hip) electric activity recorded by foramen ovale (FO) electrodes and different types of memory performances in epileptic patients. Psychological testing was performed days or weeks before electrophysiological recordings. The relative spectral power of the slow activity (below 1.25 Hz) during deep non-REM (NREM) sleep at the right pHip-Hip region correlated positively with the visual memory performance according to Rey-Osterrieth Complex Figure Test (ROCFT). Along the posterior-anterior direction of the hippocampal formation a linear increasing of correlations was observed. The relative power of the activity below 1.25 Hz at the left pHip-Hip during phasic REM sleep correlated positively with verbal learning performance and mnemonic retention values according to ROCFT. It is concluded that the pHip-Hip structures' capacity of producing high amplitude and synchronized slow (< 1 Hz) oscillation during deep NREM sleep is related to the functional power of these structures. We hypothesize that the asymmetric (side-specific) propagation of ponto-geniculo-occipital (PGO) activity to the pHip-Hip region is related to the memory correlates of phasic REM sleep.     

Psychosocial predictors of anxiety among immigrant Mexican migrant farmworkers: implications for prevention and treatment

This study examined predictors of anxiety symptomatology among immigrant Mexican migrant farmworkers in the Midwest. Its purposes were to assess the prevalence of anxiety symptoms, to examine the relationship between acculturative stress and anxiety, and to determine the variables that best predict anxiety. Heightened levels were found for overall anxiety and in the cognitive, affective, and physiological expressions of anxiety. Elevated acculturative stress, low self-esteem, ineffective social support, lack of control and choice in living a migrant farmworker lifestyle, low religiosity, and high education were significantly related to high anxiety. Findings suggest that migrant farmworkers who experience elevated acculturative stress are susceptible to the development of anxiety-related disorders and highlight the importance of establishing prevention and treatment services for migrant farmworkers.     

Attending, ignoring, and repetition: on the relation between negative priming and inhibition of return

A series of spatial localization experiments is reported that addresses the relation between negative priming and inhibition of return. The results of Experiment 1 demonstrate that slowed responses to repeated location stimuli can be obscured by repetition priming effects involving stimulus dimensions other than spatial location. The results of Experiments 2, 3A, and 3B demonstrate that these repetition priming effects may occur only when participants are required to respond to the prime display. Together, these results suggest that differences between attended and ignored repetition effects in selective attention studies of spatial localization do not provide a basis for distinguishing between spatial negative priming and inhibition of return.     

Comparative analysis of different correction methods for measuring Rod-and-Frame Test performance

A comparative analysis was conducted of five different methods for scoring the Rod-and-Frame Test to examine the convergent validities of each of the five methods with performance on the Embedded Figures Test for a sample of 408 13- to 16-yr.-olds. The scoring methods included the absolute error, the algebraic error, the absolute value of the algebraic error, the frame effect, and an assessment of relative field dependence. Correlations obtained among the five methods and the Embedded Figures Test indicated different patterns for boys and girls. In general, the method which employed the absolute value of the algebraic error yielded the strongest convergent validity coefficients with scores on the Embedded Figures Test and Group Embedded Figures Test for boys (.62 and -.54, respectively), although, for girls, the absolute algebraic error and absolute error both yielded coefficients of .50 with Embedded Figures Test scores and -.46 with Group Embedded Figures Test scores.     

Functionality and spatial relations in memory and language

We examined whether the functionality of spatial relations affects the construction and memory of information in situation models. A functional relationship involves the interaction of entities that is implied by either typical use or contextual demands. Previous research has shown that spatial relations are less likely to be encoded during comprehension unless there is extensive prior knowledge, explicit instructions to attend to spatial information, or a clear emphasis on spatial information. If the construction of a situation model is guided by a need to understand the functional structure of a situation, then functional spatial relations should be more likely to be encoded. The results of our study showed that sentences with functional spatial relations were read faster and remembered better in both recall and recognition tests than sentences with nonfunctional spatial relations.