Information limits on identification of natural surfaces by apparent colour

By adaptational and other mechanisms, the visual system can compensate for moderate changes in the colour of the illumination on a scene. Although the colours of most surfaces are perceived to be constant ('colour constancy'), some are not. The effect of these residual colour changes on the ability of observers to identify surfaces by their apparent colour was determined theoretically from high-resolution hyperspectral images of natural scenes under different daylights with correlated colour temperatures 4,300 K, 6,500 K, and 25,000 K. Perceived differences between colours were estimated with an approximately uniform colour-distance measure. The information preserved under illuminant changes increased with the number of surfaces in the sample, but was limited to a relatively low asymptotic value, indicating the importance of physical factors in constraining identification by apparent colour.     

Neighborhood Violence and Psychosocial Adjustment in Low-Income Urban African American Children: Physical Symptoms as a Marker of Child Adjustment

We examined the association between neighborhood violence and three domains of psychosocial adjustment in low-income, urban African American children: internalizing, externalizing, and physical symptoms. Based on anecdotal and empirical evidence, it was hypothesized that, relative to internalizing and externalizing problems, a stronger association would emerge between physical symptoms and neighborhood violence. Mother-reported neighborhood violence was associated with child-reported physical symptoms, but not internalizing or externalizing symptoms. Child-reported neighborhood violence was associated with child-reported internalizing, externalizing, and physical symptoms; however, neighborhood violence accounted for a greater percentage of variance in physical symptoms than the other two symptom domains. Our findings were not moderated by the age or gender of the child. We discuss the importance of physical symptoms as a marker of child adjustment in low-income, urban, African American children, as well directions for future research.     

A BEHAVIORAL INTERVENTION FOR IMPROVING VERBAL BEHAVIORS OF HEROIN ADDICTS IN A TREATMENT CLINIC

Positively reinforcing appropriate behaviors improved verbal behaviors of opioid-dependent patients in a buprenorphine treatment clinic. During B phases of an ABAB design, clients received stickers for engaging in appropriate verbal or nonverbal behaviors. Each sticker provided a chance of winning $25. No reinforcement was provided during the A phases. Appropriate verbal behaviors increased during reinforcement periods, and inappropriate verbal behaviors decreased.     

Delayed matching-to-sample performance of hens: Effects of sample duration and response requirements during the sample

Six domestic hens were trained under a delayed matching-to-sample procedure with red and green keylights as sample and comparison stimuli and a 1.5-s delay interval. The hens were trained to stop pecking the sample stimuli when a tone sounded. Duration of the sample stimuli (2 to 10 s) and the number of pecks required on the key on which these stimuli were presented (0 to 10) were altered across conditions. Both the response requirement on the sample key and the duration of sample presentations affected accuracy. These findings are in agreement with those of earlier studies using other species and somewhat different procedures.     

Differences in children's peer sociometric and attribution ratings due to context and type of aggressive behavior

Sociometric and attribution (internality and responsibility) ratings of boys performing different kinds of aggression (hostile and instrumental hitting and pushing) and of neutral behavior occurring in two contexts (provoked and unprovoked) were investigated in an analogue fashion. Thirty fifth- and sixth-grade boys viewed and rated 12 brief videotaped scenes of two unfamiliar male peers interacting, presented in one of six random orders. Provoked aggression resulted in less dislike, less worthiness of punishment, and greater attribution to external causes than unprovoked aggression. Instrumental and hostile aggression produced lower liking ratings and were viewed as more deserving of punishment than neutral behavior but did not differ from each other. Results support distinctions between provoked and unprovoked aggression but not between hostile and instrumental aggression, at least in terms of their functional impact on peer judgements.     

Assessing violent offending in serious juvenile offenders

The convergent validity of the two most frequently used methods for assessing violent offending in juveniles (i.e., selfreports and arrests) was evaluated. Participants were 87 serious juvenile offenders and their maternal figures, primarily from disadvantaged families. Validation measures tapped established behavioral, family, and peer correlates of delinquency. Results failed to support the ability of either arrests for violent crimes or selfreported violent offenses to index violent criminal behavior accurately. Several methodological features of the study support our hypothesis that the findings were not spurious. Procedural and conceptual implications of the findings are discussed.The Family and Neighborhood Services Project was funded by Grant 2H87MH43557-04 to the South Carolina Department of Mental Health from the National Institute of Mental Health. The authors extend their most sincere appreciation to Commissioner Joseph Bevilacqua, Commissioner Richard McLawhorn, Joe James, Dale Chandler, Madeline Blackwell, Kristen Rowden, Pam King, Nancy King, Nancy Yue, and Jerry DeLoye.     

Context Effects on Musical Chord Categorization: Different Forms of Top‐Down Feedback in Speech and Music?

A critical issue in perception is the manner in which top-down expectancies guide lower level perceptual processes. In speech, a common paradigm is to construct continua ranging between two phonetic endpoints and to determine how higher level lexical context influences the perceived boundary. We applied this approach to music, presenting participants with major/minor triad continua after brief musical contexts. Two experiments yielded results that differed from classic results in speech perception. In speech, context generally expands the category of the expected stimuli. We found the opposite in music: The major/minor boundary shifted toward the expected category, contracting it. Together, these experiments support the hypothesis that musical expectancy can feed back to affect lower-level perceptual processes. However, it may do so in a way that differs fundamentally from what has been seen in other domains.     

“I will accept whatever is meant for us. I wait for that—day and night”: The search for healing at a Muslim shrine in Pakistan

This paper describes an ethnographic perspective on the role of a Muslim shrine in Pakistan. Most shrines in Muslim countries represent the Sufi tradition in Islam where followers seek healing and fulfilment of their wishes using Sufi saints as intermediaries. In Pakistan, the shrine of Hazrat Abdullah Shah Ashabi provides a significant religious, social, physical, and psychological resource where people engage in religious rituals, community living and healing rituals to address physical, emotional, and social ailments. In addition to the explanatory models of misfortune described by the informants, gender, poverty, availability of formal health services, and social support seem to play a significant role in emphasizing the position of the Sufi shrine in a Muslim setting.