The role of appraisal in dysphoric affect reactivity to positive laboratory films and daily life events in depression

Hedonic deficits are linked to protracted dysphoric affect (DA) in depression, a disorder characterised by emotion context insensitivity (ECI). Recent findings from daily life studies contradict the ECI view. This study longitudinally investigated DA across laboratory and daily life contexts and the conditions associated with discrepancies in DA reactivity. Thirty-three healthy controls and 41 adults with major depressive disorder (MDD) provided responses to neutral and positive (a) films viewed in the laboratory and (b) daily events recorded over the course of three days using ecological momentary assessment (EMA) methodology. The current study reports on participants’ appraisals of films and events and their subsequent DA, both rated individually after each task and daily event. Despite large group similarities in appraisals of the positive film and life events, MDDs appraised the neutral film and neutral life events as less important (film: d?=?.58; event: η²?=?.07) and less pleasant (film: d?=?.56; event: η²?=?.18) relative to controls. While MDDs reported higher DA both in the laboratory and in daily life, they experienced larger decreases in DA during positive life events (B?=??.77, SE?=?.28, t(73)?=??2.70, p?=?.009), but not in response to the positive film relative to controls. Results indicate that higher pleasantness appraisals in daily life predicted larger decreases in DA among MDDs than controls (B?=??.24, SE?=?.06, t(73)?=??4.10, p?B?=?1.28, SE?=?.46, t(73)?=?2.77, p?=?.006). The implications of valence and relevance of context for DA reactivity and mood repair are discussed.     

Reading comprehension with the Go/No-Go procedure with compound stimuli

The present study investigated whether the Go/No-Go procedure with compound stimuli produces emergent relations among dictated words (A), pictures (B), and printed words (C) and the emergence of textual behavior (CD) using a multiple probe design across word sets. Three preschool children were exposed to 4 phases: (1) pretests for BC, CB, and CD relations, (2) pretraining with known stimuli, (3) AB and AC training, and (4) posttests for BC, CB, and CD relations. During AB and AC training, responses to A1B1, A2B2, A1C1, and A2C2 compound stimuli, but not to A1B2, A2B1, A1C2, and A2C1, were reinforced. The results showed that all participants met the learning criterion and demonstrated emergence of BC and CB relations (i.e., relations between pictures and printed words), and CD relations (i.e., textual behavior) after training. These results suggest that the Go/No-Go procedure with compound stimuli is an effective alternative for establishing reading comprehension.     

Stimulus properties of conspecific behavior

Two experiments identified the conditions in which the behavior of one bird acquired discriminative control of the behavior of a second bird. The schedule-controlled behaviors of the “stimulus” bird were differentially correlated with the components of a multiple schedule according to which the pecking of an “experimental” bird produced food. In Experiment 1, three pairs of pigeons acquired a successive discrimination and two reversals with the conspecific stimuli. Experiment 2 included a control condition in which no systematic relationship existed between the conspecific stimuli and the component schedules. While differential responding during the components of the multiple schedule was again found when the conspecific stimuli were available, differential responding did not occur in the control condition. Test conditions included in the experiments indicated that (a) the differential responding was not dependent on the discriminative properties of reinforcement, (b) the pecking of the stimulus and experimental birds was temporally interrelated, (c) the visual conspecific stimuli were critical to the maintenance of the discrimination, and (d) the observed stimulus control immediately generalized to an unfamiliar conspecific.     

Verbal behavior

The recent history and current status of the area of verbal behavior are considered in terms of three major thematic lines: the operant conditioning of adult verbal behavior, learning to be an effective speaker and listener, and developments directly related to Skinner's Verbal Behavior. Other topics not directly related to the main themes are also considered: the work of Kurt Salzinger, ape-language research, and human operant research related to rule-governed behavior.     

Spider-Phobic Children Do Not React with Differential Skin Conductance Responses to Masked Phobic Stimuli

In the present study, spider-phobic children (N = 22) were exposed to subliminal presentations of spiders, snakes, and mushrooms, while skin conductance responses (SCRs) were measured. In addition, pre- and post-treatment symptom severity data were obtained. As a group, spider-phobic children did not react with differential SCRs to masked phobic pictures. In addition, no convincing evidence was found to suggest that individual variation in differential SCRs to phobic stimuli is linked to pre-treatment symptom severity or therapy outcome. These findings cast doubts on the idea that phobics' phenomenal experience of their fear as irrational and uncontrollable is a result of pre-attentive physiological fear activation.     

Kernel smoothing approaches to nonparametric item characteristic curve estimation

The option characteristic curve, the relation between ability and probability of choosing a particular option for a test item, can be estimated by nonparametric smoothing techniques. What is smoothed is the relation between some function of estimated examinee ability rankings and the binary variable indicating whether or not the option was chosen. This paper explores the use of kernel smoothing, which is particularly well suited to this application. Examples show that, with some help from the fast Fourier transform, estimates can be computed about 500 times as rapidly as when using commonly used parametric approaches such as maximum marginal likelihood estimation using the three-parameter logistic distribution. Simulations suggest that there is no loss of efficiency even when the population curves are three-parameter logistic. The approach lends itself to several interesting extensions.The author wishes to acknowledge the support of the National Sciences and Engineering Research Council of Canada through grant A320 and the support of Educational Testing Service during his leave there.     

Increased reinforcement when timeout from avoidance includes access to a safe place

Three experiments investigated the reinforcing value of access to a safe place during timeout from an avoidance schedule. Rats were trained on conjoint schedules in which responding both postponed shock on a free-operant avoidance schedule and produced periods of timeout on fixed-ratio schedules. In some conditions, a shelf was inserted into the operant chamber during timeout, enabling subjects to get off the grid floor. The combination of timeout and shelf maintained substantially higher response rates than the baseline avoidance schedule with ratio requirements as high as 90 (Experiment I). Adding the shelf to timeouts in one component of multiple fixed-ratio schedules of timeout resulted in higher response rates in the component where the shelf was included (Experiment II). When timeouts with and without the shelf were arranged on concurrent schedules, the shelf-timeout combination was preferred, even when of shorter duration than timeout alone (Experiment III). In all three experiments, subjects climbed on the shelf, although all shocks were cancelled during timeout periods. The results could not be accounted for solely in terms of the reinforcing properties of changes in shock rates, but required an interpretation that ascribed conditioned reinforcing value to stimuli associated with such changes.     

Brief exposure to contingent reinforcement produces a sustained increment in the strength of an elicited response.

Squirrel monkeys' lever pressing produced by response-independent shock was measured before, and for an extended period following, exposure to a shock-avoidance procedure. Following avoidance training, the frequency of responding increased by multiples of 10 to 50 across subjects and evidence little or no decrement for up to 6 months of postreinforcement testing. Manual responding produced by intense environmental stimulation may be substantially strengthened by a brief history of reinforcement, such that it is sustained over long periods without reinforcement.     

An optimized facial stimuli paradigm for hybrid SSVEP+P300 brain computer interface

In this paper, hybrid BCI that merges Event Related Potentials (P300) and Steady State visual Evoked Potentials (SSVEP) simultaneously is proposed to enhance the performance of Four-choice command system. Here we integrate human facial structure in external visual stimulus to evoke stronger cortical responses in hybrid SSVEP+P300 BCI & compare it with non-face stimuli. We also addressed question of feasibility of eliciting one potential by face & other by non-face stimuli. To evoke SSVEP & P300 responses, paradigms with non-face stimuli, neutral face stimuli, and facial expression changes stimuli are proposed. We also projected additional paradigm where SSVEP is elicited by non-face and P300 by flashing different facial expressions. Results proved the last paradigm evoke stronger cortical potentials and thereby improve system accuracy and ITR than other paradigms. Author discussed external stimulus parameters that might affect simultaneous evocation of multiple brain potentials and their deterioration effect on individual potentials.     

Schedule thinning following communication training: using competing stimuli to enhance tolerance to decrements in reinforcer density

Functional communication training (FCT) is a widely used treatment for individuals with developmental disabilities who exhibit severe behavior problems. One inherent challenge of employing FCT as a treatment in the community is that reinforcement for appropriate communication cannot always be immediate or even possible in some circumstances. Of the few studies that have incorporated some form of schedule thinning for communication, most have reported disruption of communication or increases in problem behavior when the schedule of reinforcement is thinned. In the current study, we compared FCT with extinction to FCT with extinction and access to competing stimuli. After conducting a functional analysis, a competing stimulus assessment was performed to identify stimuli that produce reinforcement that ostensibly competes with reinforcement that maintains problem behavior. It was hypothesized that FCT with competing stimuli would result in more stable reductions in problem behavior during schedule thinning, which would ultimately result in quicker achievement of the treatment goal (low levels of problem behavior under the terminal reinforcement schedule for communication) than FCT without competing stimuli. Results confirmed this hypothesis.