Two pathways to stimulus encoding in category learning?

Category learning theorists tacitly assume that stimuli are encoded by a single pathway. Motivated by theories of object recognition, we evaluated a dual-pathway account of stimulus encoding. The part-based pathway establishes mappings between sensory input and symbols that encode discrete stimulus features, whereas the image-based pathway applies holistic templates to sensory input. Our experiments used rule-plus-exception structures, in which one exception item in each category violates a salient regularity and must be distinguished from other items. In Experiment 1, we found discrete representations to be crucial for recognition of exceptions following brief training. Experiments 2 and 3 involved multisession training regimens designed to encourage either part- or image-based encoding. We found that both pathways are able to support exception encoding, but have unique characteristics. We speculate that one advantage of the part-based pathway is the ability to generalize across domains, whereas the image-based pathway provides faster and more effortless recognition.     

Specificity of cognitive and behavioral variables to Positive and Negative Affect

The Tripartite Model proposes that a combination of greater Negative Affect (NA) and reduced Positive Affect (PA) contributes to depressive symptoms. The purpose of this study was to test a model of affective experience in which cognitive variables (i.e., negative cognitions and appraisals) are uniquely related to NA but not PA, and in which behavioral variables (i.e., activity participation) are uniquely associated with PA but not NA. Participants included 88 spousal Alzheimer caregivers (mean age = 74 years). Multiple regression models, in which negative cognitions (i.e., helplessness, blames self, and negative appraisals) and activity participation (i.e., frequency of engaging in social and recreational activities) were used to predict depressive symptoms, PA and NA. Results indicated that while helplessness, blaming oneself, negative appraisals, and activity participation all significantly predicted depressive symptoms, only negative cognitive variables significantly predicted NA, and only activity participation significantly predicted PA. These data confirm that depressive experience consists of two relatively independent components - increased Negative Affect and reduced Positive Affect - which have unique correlates in negative cognitions and activity participation. If confirmed, the findings suggest the utility of focusing interventions on each of these components in the management of depressive symptoms.     

The Biobehavioral Model of Persuasion: Generating Challenge Appraisals to Promote Health1

By borrowing from the biopsychosocial model of challenge and threat, we may understand when health communications adequately motivate behavior change or when they are overly distressing and inhibit behavior change. The present studies were guided by the biobehavioral model of persuasion, which predicts that different health appeals should evoke different appraisals, as well as psychological and physiological responses that motivate the adoption or rejection of health behaviors. Challenging messages should be associated with approach motivational tendencies, whereas threatening messages should be linked to avoidance. Findings from 2 experiments support the biobehavioral model of persuasion and offer mechanisms that confer message effectiveness. By understanding the psychological and physiological processes that drive message effectiveness, message designers can create more effective health appeals.     

Evidence for an explanation advantage in naïve biological reasoning

The present studies compare young children's explanations and predictions for the biological phenomenon of contamination. In Study 1, 36 preschoolers and 24 adults heard vignettes concerning contamination, and were asked either to make a prediction or to provide an explanation. Even 3-year-olds readily supplied contamination-based explanations, and most children mentioned an unseen mechanism (germs, contact through bodily fluids). Moreover, unlike adults who performed at ceiling across both explanation and prediction tasks, children were significantly more accurate with their explanations than their predictions. In Study 2, we varied the strength of cues regarding the desirability of the contaminated substance (N=24 preschoolers). Although desirability affected responses, for both levels of desirability participants were significantly more accurate on explanation than prediction questions. Altogether, these studies demonstrate a significant "explanation advantage" for children's reasoning in the domain of everyday biology.     

A systematic examination of different parameters of presession exposure to tangible stimuli that maintain problem behavior

We examined the effects of three different presession conditions on tangibly maintained problem behavior for 2 students with autism, using individual-participant multielement designs. First, an analogue functional analysis demonstrated that problem behavior was maintained by access to tangible items. Next, topographies of item rejection were identified. Finally, students were exposed to (a) brief access, (b) no access, and (c) satiation to the tangible items prior to tangible sessions. The results demonstrated high levels of problem behavior following the brief-access and no-access presession conditions and low levels of problem behavior following the satiation condition. The findings are discussed in the context of how satiation might best be defined for these sorts of evaluations.     

Sex Differences in the Effects of Neighborhood Socioeconomic Disadvantage and Social Organization on Rural Adolescents’ Aggression Trajectories

We determined whether effects of neighborhood socioeconomic disadvantage on trajectories of aggression were moderated or mediated by neighborhood social organization and examined sex differences in neighborhood effects for rural adolescents. We used five waves of survey data collected over 2.5 years linked with neighborhood data from interviews with parents and the US Census. The sample (N = 5,118) was 50.1% female, 52.0% white and 38.3% African–American; average age at baseline was 13.1 years. Multilevel growth curve models for both girls and boys showed no significant interactions between neighborhood socioeconomic disadvantage and indicators of social organization. Neither sample showed evidence of mediated effects. In main effects models, neighborhood disadvantage was associated with the average aggression trajectory for girls. For boys, the effects of neighborhood socioeconomic disadvantage and social disorganization appeared to be confounded with each other. Neighborhood disadvantage is detrimental for rural girls regardless of the level of social organization.     

Developmental history of care and control,depression and anger: Correlates of maternal sensitivity in toddlerhood

This study examined maternal sensitivity in response to toddler distress in relation to mothers' childhood care and control experiences with parents, maternal depression, and maternal anger. Fifty‐two mothers and infants participated. Mothers reported childhood care and control experiences prenatally. At 2½ years, mothers reported depressive symptoms and anger on questionnaires, and reported maternal behavior in a daily diary for 1 week, yielding ratings of maternal sensitivity to fear and anger. Results were as follows: (a) Mothers' acceptance during childhood correlated negatively with both maternal depression and maternal anger, and positively with maternal sensitivity to fear at 2½ years; (b) maternal anger mediated the association between childhood care and maternal sensitivity to fear at 2½ years; and (c) the interaction of maternal and paternal control during childhood predicted maternal sensitivity to anger at 2½ years, controlling for maternal education. When maternal control was low, paternal control was positively associated with maternal sensitivity to anger whereas when maternal control was high, paternal control was negatively associated with maternal sensitivity to anger. Results are discussed in relation to prior studies, with particular emphasis on attachment theory. Implications for preventive intervention efforts are considered.     

Alcohol consumption and handwriting: A kinematic analysis

Cerebellar dysfunction is associated with deficits in the control of movement extent, as well as changes in the amplitude and relative amounts of acceleration and deceleration and action tremor. The present study sought to identify whether cerebellar symptoms occur in the handwriting of intoxicated individuals. Twenty participants in two sub-groups (alcohol dependent and non-alcohol dependent) were asked to write four cursive letter ‘l’s on a Wacom SD420 graphics tablet before and after consumption of a dose of vodka and orange producing a peak blood alcohol concentration of 0.048%. There was a relationship between blood alcohol concentration and stroke length. Kinematic analysis of handwriting indicated increases in the relative proportions of time spent in acceleration and increases in spectral power around 4 Hz. It was found that alcohol intoxication causes symptoms of cerebellar dysfunction, and that alcohol dependent individuals had less ballistic handwriting compared to non-alcohol dependent participants.