State test‐anxiety,selective attention and concentration in university students

The principal aim of this study was to assess the level of selective attention and mental concentration before exams in a sample of university students and to determine a possible relationship between anxiety and reduction of levels of attention in this circumstance. A total of 403 university students, 176 men and 227 women, aged from 18 to 46 years, participated in the study. Of them, 169 were first‐year undergraduates, 118 were second to fourth‐year undergraduates and 116 were postgraduate Master's degree students. All of them completed the Spanish version of the Spielberger State‐Anxiety Inventory and the D2 Attention Test just before taking an exam. Our results showed that participants with lower levels of anxiety had higher levels of selective attention and mental concentration before the exam. These results specifically indicate that when anxiety levels are very high, this could over‐activate the orientating and alerting functions and to reduce the capacity of attentional control. These processes could have a negative impact on specific attentional processes and become a negative influence on performance in exams.     

Effect of temporal constraints on hemispheric asymmetries during spatial frequency processing

Studies on functional hemispheric asymmetries have suggested that the right vs. left hemisphere should be predominantly involved in low vs. high spatial frequency (SF) analysis, respectively. By manipulating exposure duration of filtered natural scene images, we examined whether the temporal characteristics of SF analysis (i.e., the temporal precedence of low on high spatial frequencies) may interfere with hemispheric specialization. Results showed the classical hemispheric specialization pattern for brief exposure duration and a trend to a right hemisphere advantage irrespective of the SF content for longer exposure duration. The present study suggests that the hemispheric specialization pattern for visual information processing should be considered as a dynamic system, wherein the superiority of one hemisphere over the other could change according to the level of temporal constraints: the higher the temporal constraints of the task, the more the hemispheres are specialized in SF processing.     

Hemispheric predominance assessment of phonology and semantics: a divided visual field experiment

The aim of the present behavioural experiment was to evaluate the most lateralized among two phonological (phoneme vs. rhyme detection) and the most lateralized among two semantic ("living" vs. "edible" categorization) tasks, within the dominant hemisphere for language. The reason of addressing this question was a practical one: to evaluate the degree of the hemispheric lateralization for several language tasks, by using the divided visual presentation of stimuli, and then choose the most lateralized semantic and phonological for mapping language in patients by using fMRI in future studies. During the divided visual field experiment by using words (semantic tasks) and pseudo-words (phonological tasks) as stimuli, thirty-nine right-handed participants were examined. Our results have shown that all tasks were significantly left hemisphere lateralized. Furthermore, the rhyme was significantly more lateralized than phoneme detection and "living" was significantly more lateralized than "edible" categorization. The rhyme decision and "living" categorization will be used in future fMRI studies for assessing hemispheric predominance and cerebral substrate for semantics and phonology in patients. Our results also suggest that the characteristics of stimuli could influence the degree of the hemispheric lateralization (i.e., the emotional charge of stimuli for words and the position of the phoneme to be detected, for pseudo-words).     

Some effects of stimulant medication on response allocation: a double-blind analysis

Children who are diagnosed with attention deficit hyperactivity disorder (or who engage in behavior consistent with such a diagnosis) are often prescribed stimulant medications for hyperactive or inattentive behaviors. However, the mechanisms by which stimulant medications affect individuals' behavior are rarely evaluated. The purpose of the current study was to evaluate the effects of stimulant medication on response allocation when antecedents and consequences were held constant and equated. Results indicated that the presence of an amphetamine medication (Adderall) influenced response allocation across two concurrently available responses while all other stimulus conditions were held constant.     

A paradoxical effect of presession attention on stereotypy: antecedent attention as an establishing, not an abolishing, operation

Previous studies have shown that presession attention for problem behavior can serve as an abolishing operation when attention functions as a positive reinforcer. In the current study, we show that the stereotypy of a child with severe disabilities was undifferentiated during standard analogue functional analysis conditions. However, when noncontingent presession attention was provided, stereotypy occurred for social attention as a positive reinforcer, suggesting that the antecedent manipulation functioned as an establishing operation.     

Exogenous attention differentially modulates the processing of categorical and coordinate spatial relations

Carrasco and her colleagues have suggested that exogenous attention reduces the size of receptive fields at an attended location (Gobell & Carrasco, 2005; Yeshurun & Carrasco, 1998, 2000). Based on the hypothesis that categorical and coordinate spatial relations are more efficiently processed by smaller and larger receptive fields, respectively, we predicted that exogenous attention would be more beneficial to the processing of categorical spatial relations than coordinate spatial relations while it would disrupt the processing of coordinate spatial relations. To test these hypotheses, participants were tested using a variant of Posner's (1980) attentional cueing paradigm. Exogenous attention produced larger facilitative effects on categorical spatial processing than on coordinate spatial processing at a short cue-target stimulus onset asynchrony (100 ms, Experiment 1, N = 28), and this result was replicated regardless of cue size in Experiment 2 (N = 24). When the coordinate judgment was sufficiently difficult, exogenous attention disrupted the processing of coordinate spatial relations (Experiment 3, N = 28). These findings indicate that exogenous attention can differentially modulate the processing of categorical and coordinate spatial relations.     

An investigation of differential reinforcement of alternative behavior without extinction

We manipulated relative reinforcement for problem behavior and appropriate behavior using differential reinforcement of alternative behavior (DRA) without an extinction component. Seven children with developmental disabilities participated. We manipulated duration (Experiment 1), quality (Experiment 2), delay (Experiment 3), or a combination of each (Experiment 4), such that reinforcement favored appropriate behavior rather than problem behavior even though problem behavior still produced reinforcement. Results of Experiments 1 to 3 showed that behavior was often sensitive to manipulations of duration, quality, and delay in isolation, but the largest and most consistent behavior change was observed when several dimensions of reinforcement were combined to favor appropriate behavior (Experiment 4). Results suggest strategies for reducing problem behavior and increasing appropriate behavior without extinction.     

Functional analysis and treatment of aggression maintained by preferred conversational topics

After an initial functional analysis of a participant's aggression showed unclear outcomes, we conducted preference and reinforcer assessments to identify preferred forms of attention that may maintain problem behavior. Next, we conducted an extended functional analysis that included a modified attention condition. Results showed that the participant's aggression was maintained by access to preferred conversational topics. A function-based intervention decreased aggression and increased an appropriate communicative response.