Nonhomogeneous resolution of images of natural scenes

The aim of this research is to model and simulate the loss of visual resolution as a function of retinal eccentricity in the perception of natural scenes. The model of visual resolution is based on a space-variant low-pass filter, having a variable convolution kernel according to retinal eccentricity. The parameters of the model are computed from psychophysical measures of visual acuity as a function of retinal eccentricity. The implementation of the model allowed us to generate images of scenes with nonhomogeneous space-variant resolution, simulating the filtering executed by the eye. These scenes are used to test and optimise the model by means of experiments in static vision (through tachistoscopic presentations) and in dynamic vision where the resolution of the scene is computed, in real-time, as a function of the location of gaze.     

When false memories do not occur: not thinking of the lure or remembering that it was not heard?

The aim of the present study was to evaluate two explanations for the non-occurrence of false memories in the Deese-Roediger-McDermott (DRM) paradigm. One explanation was that a critical lure is not recalled because the list failed to evoke it in the participant's mind. Another possible explanation was that the participant would identify the critical lure and would remember, at the time of recall, that the lure was not produced by an external source. In order to explore these two possible explanations for the non-occurrence of false memories, an experimental phase was added to the usual DRM paradigm: participants were asked to recall items they thought of but did not recall because these items were not members of the list presented by the experimenter. Among participants who did not recall the critical lure during the standard recall task, those who recalled the critical lure during the additional phase outnumbered those who did not recall it. This result is more consistent with the second explanation than with the first one.     

Encoding specificity manipulations do affect retrieval from memory

In a recent article, P.A. Higham (2002) [Strong cues are not necessarily weak: Thomson and Tulving (1970) and the encoding specificity principle revisited. Memory &Cognition, 30, 67-80] proposed a new way to analyze cued recall performance in terms of three separable aspects of memory (retrieval, monitoring, and report bias) by comparing performance under both free-report and forced-report instructions. He used this method to derive estimates of these aspects of memory in an encoding specificity experiment similar to that reported by D.M. Thomson and E. Tulving (1970) [Associative encoding and retrieval: weak and strong cues. Journal of Experimental Psychology, 86, 255-262]. Under forced-report instructions, the encoding specificity manipulation did not affect performance. Higham concluded that the manipulation affected monitoring and report bias, but not retrieval. I argue that this interpretation of the results is problematic because the Thomson and Tulving paradigm is confounded, and show in three experiments using a more appropriate design that encoding specificity manipulations do affect performance in forced-report cued recall. Because in Higham's framework forced-report performance provides a measure of retrieval that is uncontaminated by monitoring and report bias it is concluded that encoding specificity manipulations do affect retrieval from memory.     

Family functioning and early onset of sexual intercourse in Latino adolescents

The purpose of this study was to identify factors associated with early onset of sexual intercourse. Within an ecological system's conceptual framework, familial factors associated with early onset of sexual activity were identified in a sample of 425 adolescents from San Juan metro area schools. Measures included questions about sexual activity, sexual permissiveness, and such familial variables as: discipline, parental supervision, and parental support. Significant relationships were observed between early onset of sexual intercourse and parental supervision, discipline, parental support, and parents' marital status. Results suggest the key role of parents and family in prevention of HIV-risk behaviors among adolescents in terms of delaying sexual onset. Overall, the study described youths who postponed sexual activity as having greater support, supervision, and parental involvement.     

Distress tolerance as a predictor of early treatment dropout in a residential substance abuse treatment facility

A large percentage of individuals who enter residential substance abuse treatment drop out before completing treatment. Given that early treatment dropout places individuals at an increased risk for relapse, identifying the mechanisms underlying treatment dropout would have several important theoretical and clinical implications. In the current study, the authors examined levels of psychological and physical distress tolerance as a predictor of early treatment dropout in a residential substance abuse treatment facility. In a sample of 122 individuals entering a residential substance abuse treatment facility, level of psychological distress tolerance was predictive of early treatment dropout above and beyond relevant self-report variables. There was no relationship between physical distress tolerance and early treatment dropout. Implications for future studies and treatment development or modification are discussed.     

Intention memory and achievement motivation: volitional facilitation and inhibition as a function of affective contents of need-related stimuli

Replicating findings of J. Kuhl and M. Kazén (1999), reduction or removal of Stroop interference was achieved after short exposure to primes eliciting positive affect. This effect was need specific: Stroop interference removal (volitional facilitation) was found with positive primes related to achievement needs but not with positive primes related to affiliation or power needs. Five studies are reported. College students and unemployed university graduates participated in 2 studies each and branch managers of a large insurance company in 1 study. Whereas Stroop interference reduction or removal was found in all groups after positive-achievement primes, the 2 groups of unemployed persons additionally showed a significant increase of Stroop interference (volitional inhibition) after exposure to primes related to negative achievement episodes. Results are discussed in the context of Kuhl's personality systems interactions theory.     

Effects of reinforcement history on response rate and response pattern in periodic reinforcement

Several researchers have suggested that conditioning history may have long-term effects on fixed-interval performances of rats. To test this idea and to identify possible factors involved in temporal control development, groups of rats initially were exposed to different reinforcement schedules: continuous, fixed-time, and random-interval. Afterwards, half of the rats in each group were studied on a fixed-interval 30-s schedule of reinforcement and the other half on a fixed-interval 90-s schedule of reinforcement. No evidence of long-term effects attributable to conditioning history on either response output or response patterning was found; history effects were transitory. Different tendencies in trajectory across sessions were observed for measures of early and late responding within the interreinforcer interval, suggesting that temporal control is the result of two separate processes: one involved in response output and the other in time allocation of responding and not responding.     

The dynamics of self-esteem in adults over a 6-month period: an exploratory study

In this exploratory study, the authors examined the dynamics of self-esteem in 8 adults over a 6-month period. Each participant (M age = 29.4 years, SD = 7.9, SEM = 2.8) completed a single item from the Physical Self Inventory (G. Ninot, M. Fortes, & D. Delignières, 2001) using a 10-cm visual analog scale (horizontal line), twice a day between 7:00 and 9:00 a.m. and between 7:00 and 9:00 p.m. Time series analyses, including autocorrelation and autoregressive integrated moving average (ARIMA) procedures, showed that global self-esteem dynamics were neither stable, stationary, nor random. The ARIMA procedures indicated that this perceived dimension functioned as a moving average (0, 1, 1) without a significant constant, thus suggesting a short-term dynamic adjustment. This pattern is a typical signature of a complex system submitted to several constraints and not an indication of personality trait or state.     

Early psychological consequences of the March 11, 2004, terrorist attacks in Madrid, Spain

On March 11, 2004, Al-Qaeda set off 10 bombs on several train routes in Madrid. 192 people were killed and 2,000 wounded. In this study, 1,179 questionnaires were administered Week 2 after the attacks to residents 18 years and over from the affected geographical areas. The questionnaire included items about sociodemographic variables and exposure to the attacks. Psychological effects were assessed as presence of acute stress and depressive symptomatology and functional impairment. 46.7% of the sample presented symptomatology of acute stress and 49.6% depressive symptoms. Among the symptoms of acute stress, the most frequent were re-experiencing (72.5%) and dissociative symptoms (71.8%). The chief predicting variables in symptomatology were being female, over 65 yr. old, and a habitual train user. The large number of affected people was refined with an item analysis and the consideration of severity of interference in psychosocial functioning.     

The Spanish version of Betts' Questionnaire Upon Mental Imagery

Sheehan's shortened form of Betts' Questionnaire Upon Mental Imagery is one of the most widely used inventories for measuring imaging. Participants were 562 undergraduate students (414 women and 148 men), with a mean age of 20.2 yr. In a principal components analysis followed by varimax orthogonal rotation for the Spanish version, eight factors were identified, six of which coincide with those of the original English version. Internal consistency was .92 (Cronbach alpha). Scores on the Betts Questionnaire Upon Mental Imagery correlated -.34 with those on the Gordon Test of Visual Imagery Control, .58 with those on the Vividness of Visual Imagery Questionnaire, and .02 with the Verbalizer-Visualizer Questionnaire.