Visual persistence of spatially filtered images

Periodic stimuli such as sine-wave gratings and checkerboard patterns have been used in many studies of visual perception. It is well known that with such stimuli, visual persistence increases as spatial frequency increases and as contrast decreases. It is not clear, however, that similar relationships obtain for aperiodic stimuli such as natural images. Digitized images of objects (a face and a vase) were submitted to two-dimensional Fourier analysis. Four pairs of spatial frequency band-limited images were created for each image. Each pair consisted of a normal (NP) and a scrambled (SP) phase version, with the magnitude spectrum and space-averaged luminance the same within each pair. Filter bandwidths were one octave wide. Threshold persistence was measured for each spatially filtered image. Visual persistence for SP images increased significantly as spatial frequency increased, whereas no significant differences were found for NP images. This suggests that the temporal processing of complex, aperiodic visual images is influenced by the spatial frequency and contrast of local features within the image and cannot be predicted by space-averaged estimates of contrast and spatial frequency.     

The effects of spatial phase on reaction time to spatially filtered images

Summary Many studies of visual perception have used periodic stimuli such as sine-wave gratings and checker-board patterns. It is well known that reaction time (RT) to such stimuli increases with increasing spatial frequency and decreasing contrast. While this is the case with periodic stimuli it is not clear that these relationships obtain for aperiodic stimuli such as natural scenes. A digitized image of an object (a vase) was submitted to two-dimensional Fourier analysis. Four pairs of spatial frequency band-limited images were created for each image. Each pair consisted of a normal-phase (NP) and a scrambled-phase (SP) version, with the magnitude spectrum and space-averaged luminance the same within each pair. Filter band-widths were 1 octave wide. Manual RT was measured for onset and offset of each spatially filtered image. Mean RT for SP images increased significantly with increasing spatial frequency, while no other significant differences were found with the NP images. This suggests that the temporal processing of complex, aperiodic images is influenced by the spatial frequency and contrast of local regions within the image, rather than by the space-averaged contrast of the entire image, and cannot be predicted by global estimates of contrast and spatial frequency.     

Violence in College Students' Dating Relationships1

In a survey of 504 college students examining predictors of violence in heterosexual relationships, over half of both men and women had committed at least one physically violent act, and men more often than women reported having been the victims of such acts. Most respondents who reported some experience with violence had both committed and received it, were involved in relatively few different types of violence, and first experienced violence when a relationship had moved beyond the casual dating stage. Modest associations between physical violence and sexual aggression were uncovered. In a series of discriminant analyses, men who abused their partners were not readily distinguished from men who did not, but tended to be young, low in family income, traditional in attitudes toward women, abused as children, currently living with a woman, and from Appalachian areas. Women who abused were more readily discriminated and scored low in social desirability, were abused as children, and were from non-Appalachian areas. Men who were abused were likely to be living with a woman and tended to be low in family income; similarly, cohabitation was related among women to being a target of violence, as were having been abused as a child and scoring low in social desirability. Findings are related to those of other studies of dating abuse, as well as to the family violence and aggression literatures.     

Infant state in relation to its environmental context

Two neonatal intensive care units (NICU) were observed every 15 minutes for at least 72 consecutive hours. Although infants on both NICUs were exposed to considerable amounts of stimulation, there were differences between the units for each environmental measure in the amount of stimulation and/or the pattern of circadian periodicity. The two NICUs also differed in the amount of time infants spent in various states and in the pattern of state periodicity. In general, the diurnal rhythms of the infant states were associated with the diurnal rhythms of different environmental events; furthermore, the patterns of association were not the same on the two NICUs. The results point to potential problems in depicting a “typical” NICU. More importantly, they suggest that the environmental of NICUs has a recognizable influence on aspects of their inhabitants' behavior and that the nature of influence is different from NICU to NICU. The effects are potentially significant for physical, social, and cognitive development.     

Acute Alcohol Co‐Ingestion and Hospital‐Treated Deliberate Self‐Poisoning: Is There an Effect on Subsequent Self‐Harm?

The aim of this study was to determine the relationship between alcohol co‐ingestion in an index deliberate self‐poisoning (DSP) episode with repeated DSP and subsequent suicide. A retrospective cohort study was conducted involving 5,669 consecutive index presentations to a toxicology service following DSP between January 1, 1996, and October 31, 2010. Records were probabilistically matched to National Coronial Information System data to identify subsequent suicide. Index DSPs were categorized on co‐ingestion of alcohol, and primary outcomes analyzed were repetition of any DSP, rates of repeated DSP, time to first repeat DSP, and subsequent suicide. Co‐ingestion of alcohol occurred in 35.9% of index admissions. There was no difference between those who co‐ingested alcohol (ALC+) and those who did not co‐ingest alcohol (ALC?) in terms of proportion of repeat DSP, number of DSP events, or time to first repeat DSP event. Forty‐one (1.0%) cases were probabilistically matched to a suicide death; there was no difference in the proportion of suicide between ALC+ and ALC? at 1 or 3 years. There was no significant relationship between the co‐ingestion of alcohol in an index DSP and subsequent repeated DSP or suicide. Clinically, this highlights the importance of mental health assessment of patients that present after DSP, irrespective of alcohol co‐ingestion at the time of event.     

Inspecting pictures for information to verify a sentence: Eye movements in general encoding and in focused search

When we see combinations of text and graphics, such as photographs and their captions in printed media, how do we compare the information in the two components? Two experiments used a sentence-picture verification task in which statements about photographs of natural scenes were read in order to make a true/false decision about the validity of the sentence, and in which eye movements were recorded. In Experiment 1 the sentence and the picture were presented concurrently, and objects and words could be inspected in any order. In Experiment 2 the two components were presented one after the other, either picture first or sentence first. Fixation durations on pictures were characteristically longer than those on sentences in both experiments, and fixations on sentences varied according to whether they were being encoded as abstract propositions or as coreferents of objects depicted in a previously inspected picture. The decision time data present a difficulty for existing models of sentence verification tasks, with an inconsistent pattern of differences between true and false trials.     

Reminders of an agentic ingroup buffer disease uncontrollability

Chronic illness has negative impacts beyond those on physical health. In particular, because it is often experienced as uncontrollable, chronic illness might reduce people's general sense of personal control and, subsequently, personal well-being. Drawing on recent theory and research, we proposed and tested in four experiments (N_total = 1323) a potential buffer to these negative effects: thinking about an agentic social ingroup in one's life. In Study 1, patients suffering from a chronic illness that was either high or low in medical disease controllability were asked either to think about an agentic ingroup or a personal issue. Low perceived disease-related control was associated with low perceived personal control only when participants' personal self, but not when their ingroup, was salient. In three follow-up vignette studies, we asked participants to take the perspective of a person who suffered from a health problem of low medical disease controllability and attended a self-help group that was described as either high or low in agency. The findings supported the predicted buffering effect: participants who reflected on a target suffering from a low control disease thought that the target would experience more personal control when the agentic (vs. the nonagentic) self-help group was salient. These findings suggest ingroups can serve as a source of personal control in the context of health-related threats to the extent that they are perceived as agentic. Thus, focusing on agentic properties of (health-related) ingroups might be a promising novel strategy when designing effective group-based interventions to cope with chronic illness.