Diagnostic spatial frequencies and human efficiency for discriminating actions

Humans extract visual information from the world through spatial frequency (SF) channels that are sensitive to different scales of light-dark fluctuations across visual space. Using two methods, we measured human SF tuning for discriminating videos of human actions (walking, running, skipping and jumping). The first, more traditional, approach measured signal-to-noise ratio (s/n) thresholds for videos filtered by one of six Gaussian band-pass filters ranging from 4 to 128 cycles/image. The second approach used SF "bubbles", Willenbockel et al. (Journal of Experimental Psychology. Human Perception and Performance, 36(1), 122-135, 2010), which randomly filters the entire SF domain on each trial and uses reverse correlation to estimate SF tuning. Results from both methods were consistent and revealed a diagnostic SF band centered between 12-16 cycles/image (about 1-1.25 cycles/body width). Efficiency on this task was estimated by comparing s/n thresholds for humans to an ideal observer, and was estimated to be quite low (>.04%) for both experiments.     

Transgender youth and life-threatening behaviors

Sexual minority status is a key risk factor for suicide among lesbian, gay, and bisexual youth; however, it has not been studied among transgender youth. Fifty-five transgender youth reported on their life-threatening behaviors. Nearly half of the sample reported having seriously thought about taking their lives and one quarter reported suicide attempts. Factors significantly related to having made a suicide attempt included suicidal ideation related to transgender identity; experiences of past parental verbal and physical abuse; and lower body esteem, especially weight satisfaction and thoughts of how others evaluate the youths' bodies. Sexual minority status is a key risk factor for life-threatening behaviors among transgender youth.     

Work Barriers in the Context of Pathways to the Employment of Welfare-to-Work Clients

The ability of welfare-to-work clients to leave the welfare rolls and stay in the labor force is often limited by the work barriers they face. Using a sample of 1,404 female welfare-to-work clients we first examined the structure of work barriers and then tested their contribution to current work status in the context of a structural equation model that incorporated other central pathways to employment. Whereas work barriers included diverse factors ranging from lack of transportation to low quality jobs, they were shown to constitute a uni-dimensional construct. Furthermore, work barriers had a net adverse effect on employment outcomes, controlling for job search self-efficacy and employment intention. We conclude with discussion of implications for the development of welfare-to-work programs and interventions that target low-income women.     

Social influences on creativity: the effects of contracted-for reward

Three studies were conducted to examine the effects of reward on children's and adult's creativity. The primary hypothesis was that explicitly contracting to do an activity in order to receive a reward will have negative effects on creativity, but receiving no reward or only a noncontracted-for reward will have no such negative effects. All three studies provided support for this hypothesis. Moreover, this support appears to be strong and generalizable across different subject populations, reward types, reward presentations, and creativity tasks. Possible mechanisms for the phenomenon are discussed.     

Cross-examination of the expert witness: Do hostile tactics affect impressions of a simulated jury?

Ninety-one introductory psychology students viewed a videotape of a simulated personal damage trial in which a psychologist expert witness testified about a plaintiff's psychological problems resulting from trauma. The defense attorney's cross-examination tactics, employed against the expert witness, were varied in the videotape. A 2 × 2 factorial design was used, with leading versus nonleading questions and a hostile versus nonhostile attorney. An interaction effect was obtained, in which a hostile attorney using leading questions and a nonhostile attorney using nonleading questions were perceived as least effective.     

Hypertension and cognitive function

Previous research indicates that blood pressure may impact a variety of cognitive functions, including short-term memory, abstract reasoning, visual-spatial abilities, and attention (Boller, Vrtunski, Mack, & Kim, 1977; Elias, Robbins, Schultz, & Pierce, 1990; Franceschi, Tancredi, Smirne, Mercinelli, & Canal, 1982; Mazzucchiet al., 1986). However, studies which have assessed the cognitive functioning of hypertensive adults have offered conflicting results, particularly when hypertension levels were in the mild range (e.g., Bolleret al., 1977; Eliaset al., 1990; Elias, Wolf, D'Agostino, Cobb, & White, 1993; Farmeret al., 1987, 1990; Franceschiet al., 1982; Pérez-Stable, Coates, Halliday, Gardiner, & Hauck, 1992; Schmidtet al., 1991; Waldstein, Ryan, Manuck, Parkinson, & Bromet, 1991). A number of factors may contribute to the inconsistent findings in this area. Researchers have employed a wide range of neuropsychological instruments to assess varying domains of cognitive function. Sample sizes in some studies have been too small to ensure sufficient power. Finally, studies have employed varying methodological control over potential confounding factors such as concurrent medical conditions, alcohol abuse, psychiatric disorders, or antihypertensive medication. This study compared male veterans with blood pressures in the mildly hypertensive range (n=166) to normotensive veterans (n=176) on neuropsychological measures of verbal fluency, visual-spatial ability, verbal and visual memory, dexterity, attention, and executive functions. Results revealed that, after controlling for differences in education and income, there was no relationship between mild hypertension and combined measures of cognitive performance. The present findings suggest that mild hypertension alone has little effect on cognitive function in adults.     

Object Recognition Difficulty in Visual Apperceptive Agnosia

Two patients with visual apperceptive agnosia were examined on tasks assessing the appreciation of visual material. Elementary visual functioning was relatively preserved, but they had profound difficulty recognizing and naming line drawings. More detailed evaluation revealed accurate recognition of regular geometric shapes and colors, but performance deteriorated when the shapes were made more complex visually, when multiple-choice arrays contained larger numbers of simple targets and foils, and when a mental manipulation such as a rotation was required. The recognition of letters and words was similarly compromised. Naming, recognition, and anomaly judgments of colored pictures and real objects were more accurate than similar decisions involving black-and-white line drawings. Visual imagery for shapes, letters, and objects appeared to be more accurate than visual perception of the same materials. We hypothesize that object recognition difficulty in visual apperceptive agnosia is due to two related factors: the impaired appreciation of the visual perceptual features that constitute objects, and a limitation in the cognitive resources that are available for processing demanding material within the visual modality.     

Septal influences on operant responding in the rat.

The afferent and efferent connections of the septum with the hippocampus (fornix) of with the hypothalamus and lower brain stem (medial forebrain bundle) were transected by means of an encephalotome near the point where these pathways enter or leave the septal area. A transection of the fornix that produced minimal direct damage to cellular components of the septum of hippocampus reproduced the effects of large septal lesions on responding in several temporally defined paradigms that involve periods of response suppression (differential reinforcement of low rates, discriminated Sidman avoidance, fixed interval). Transection of the medial forebrain bundle fibers that interconnect the septum with the hypothalamus and lower brain stem did not affect behavior in any of these paradigms. These observations should be veiwed in the context of the results of earlier investigations which demonstrated that transection of the medial forebrain bundle reproduces several other components of the septal lesion syndrome.