Threshold exposure duration as a function of luminance for visual recognition

Threshold exposure duration was measured at set luminances for recognition at successively higher criteria of 1, 2, 3, 4, and 5 correct letters in nonsense words. Two sizes of letters were used and triads of Landolt “Cs” were compared with letters. Tachistoscopic procedures were the typical ascending seriesin the method of limits and pre- and postexposure light adaptation. Obtained log t vs log I functions were two-part straight line curves both describable by the equation, log t + log I^k = log C, but with k and C abruptly changing at a certain I. Reciprocity (k = 1) held only for low Is and the low criterion; as criterion was raised at low Is k became less negative (about ?.60 at five correct) for both sizesand for “Cs.” At higher Is, k shifted from ?.25 to ?.40 with increasing criterion for large letters, but variedaround ?.45 at all criteria for small. The lower the criterion, the lower the / and t at which k and C abruptly changed for large letters, but only t was lower for small. Changes in t with acuity requirement change, and from one criterion level to the next, were not uniform over all Is. Results may reflect obscuring procedural factors or basic properties of visual recognition processes. Some interpretations in terms of procedural variables are offered. It appears more likely that visual recognition involves central processes for which time is needed in excess of that for summation of luminances for mere detection by sensory processes, as expressed in Bloch s’ reciprocity law.     

The dissociation of position and extent in Müller-Lyer figures

Three experiments were designed to determine whether Müller-Lyer figures cause a misperception of the positions of their fins and, if they do, whether it is commensurate with the distortion of extent. Observers marked the visible intersection of shaft and fins either with their unseen hands or with their visible hands after the figure had been removed from view. In the former case, no systematic distortions of position were evident. In the latter case, there were small, systematic distortions of position, which were significantly smaller when the observers fixated the target vertex than when they fixated the center of the figure. These differences are discussed in terms of the probable similarities between the control of eye movements and the control of pointing responses. Of particular importance is the finding that even the largest distortions of vertex position were much smaller than the distortions of shaft extent. The results appear to provide evidence of the independence of perceived position from perceived extent in Müller-Lyer figures and to contradict all existing theories of the illusion.     

Is EBM an Appropriate Model for Research into the Effectiveness of Psychotherapy?

Topoi - EBM, and the hierarchy of evidence it prescribes, is a controversial model when it comes to research into the effectiveness of psychotherapeutic treatments. This is due in part to the...     

Under Reporting of Suicide Ideation in US Army Population Screening: An Ongoing Challenge

Previous research in US Army Soldiers shows rates of mental health concerns as two to four times higher on anonymous surveys than on postdeployment health assessments. In this study, Soldiers presenting for health reassessment completed two questionnaires on suicide risk factors: one linked to the health assessment and one anonymous. About 5.1% of respondents reported suicide ideation on the anonymous questionnaire, 3.0% on the linked questionnaire, and 0.9% on the health reassessment. About 56.4% who reported suicide ideation anonymously told nobody of their thoughts. Current screening procedures identify only one in seven Soldiers experiencing suicide ideation and highlight the need for alternative risk‐detection strategies.     

When are moods most likely to influence consumers' product preferences? The role of mood focus and perceived relevance of moods

This program of research examined the hypothesis that moods are most likely to be used as a source of information in making evaluations and choices when consumers both focus on their moods (i.e., acknowledge and pay attention to their feelings) and perceive that moods are a relevant source of information for forming judgments. Support for this prediction was obtained when the relevance of moods was examined by manipulating relevance instructions, varying advertising cues, and manipulating product type. Further, the boundary conditions under which the combination of mood focus and perceived relevance is most influential on product preferences are identified.     

Mothers' responses to infant physical appearance

Mothers' responses to slides of infants were assessed. During individual presentations of the slides they showed increases in smiling to infant photographs in general, but showed large skin conductance responses only to pictures of their own infant. They did not look differentially at the photographs. During paired presentations, mothers looked longer at their own infant's photograph. Moreover, they looked longer at unfamiliar infants who they perceived to be high in cuteness. These findings are discussed with reference to the role of infant physical appearance in infant-adult social relations.     

Perceived social support and maternal adaptation during the transition from hospital to home care of high-risk infants

Forty-two mothers of high-risk infants who had been hospitalized in a newborn intensive care unit were interviewed approximately 2 months after hospital discharge. On standard questionnaires, they reported how much support they had received since discharge and their need for and satisfaction with support in three areas: Emotional, informational, and tangible support. Mothers also completed the Profile of Mood States, the Sleep, Feeding, and Crying Questionnaire, and the Impact of Event Scale and rated the severity of the infant's medical condition and expected developmental/health outcome. Measures of maternal adaptation and infant characteristics were subjected to exploratory factor analysis from which summary scores were constructed. One maternal adaptation factor and two infant status factors were examined in relation to social support variables, but no significant associations were found for the sample as a whole. However, satisfaction with each area of support was related to maternal adaptation when the infant's post-discharge status was relatively more severe. The results are discussed in terms of the crises of the hospital to home transition and the difficult tasks that face parents after the assumption of full responsibility for a vulnerable infant who required newborn intensive care.