Seeing with the skin

A system for converting an optical image into a tactile display has been evaluated to see what promise it has as a visual substitution system. After surprisingly little training, Ss are able to recognize common objects and to describe their arrangement in three-dimensional space. When given control of the sensing and imaging device, a television camera, Ss quickly achieve external subjective localization of the percepts. Limitations of the system thus far appear to be more a function of display resolution than limitations of the skin as a receptor surface. The acquisition of skill with the device has been remarkably similar for blind and sighted Ss.     

Animals, pain and morality

While it is widely agreed that the infliction upon innocents of needless pain is immoral, many have argued that, even though nonhuman animals act as if they feel pain, there is no reason to think that they actually suffer painful experiences. And if our actions only appear to cause nonhuman animals pain, then such actions are not immoral. On the basis of the claim that certain behavioural responses to organismic harm are maladaptive, whereas the ability to feel pain is itself adaptive, this article argues that the experience of pain should be viewed as the proximate cause of such occasionally maladaptive behaviour. But as nonhuman animals also display such maladaptive traits, we have reason to conclude that they feel pain. Hence, we have reason to hold that it is indeed possible to inflict needless pain on nonhuman animals, which would be immoral.     

College students' acceptance of potential treatments for ADHD

The purpose of the current study was to investigate the influence that the professional occupation of a consultant making a treatment recommendation may have on college students' (82 women and 52 men) acceptance of a proposed treatment for a child displaying characteristics of Attention Deficit/Hyperactivity Disorder. Consultants were special education teachers, school psychologists, or physicians. The study also examined college students' ratings of treatment acceptability associated with three frequently implemented interventions of either nonspecific medication, token economy with response cost, or time-out for children with characteristics of Attention Deficit/Hyperactivity Disorder. Analysis indicated college students found a token economy intervention was the least acceptable recommendation by a physician.     

Social and psychiatric influences on urban-rural differentials in Australian suicide

The purpose of this study was to investigate urban-rural differentials in Australian suicide rates, and to examine influences that previously have remained largely speculative. Suicide rates for males (all ages and young adults) were significantly higher in rural areas compared to urban areas. Urban-rural suicide rate differences in males were rendered nonsignificant after adjustment for migrant and area socioeconomic status. Adjusting for mental disorder prevalence, in addition to migrant status, reduced the excess suicide risk in rural areas; the excess was reduced further with addition of mental health service utilization. The implications of this study are that socioeconomic circumstances in rural populations contribute to higher male suicide rates compared to urban areas, but these conditions may be partly mediated by mental disorder prevalence and mental health service utilization.     

A common oscillator for perceptual rivalries?

Perceptual rivalry is an oscillation of conscious experience that takes place despite univarying. if ambiguous, sensory input. Much current interest is focused on the controversy over the neural site of binocular rivalry, a variety of perceptual rivalry for which a number of different cortical regions have been implicated. Debate continues over the relative role of higher levels of processing compared with primary visual cortex and the suggestion that different forms of rivalry involve different cortical areas. Here we show that the temporal pattern of disappearance and reappearance in motion-induced blindness (MIB) (Bonneh et al, 2001 Nature 411 798-801) is highly correlated with the pattern of oscillation reported during binocular rivalry in the same individual. This correlation holds over a wide range of inter-individual variation. Temporal similarity in the two phenomena was strikingly confirmed by the effects of the hallucinogen LSD, which produced the same, extraordinary, pattern of increased rhythmicity in both kinds of perceptual oscillation. Furthermore. MIB demonstrates the two properties previously considered characteristic of binocular rivalry. Namely the distribution of dominance periods can be approximated by a gamma distribution and, in line with Levelt's second proposition of binocular rivalry, predominance of one perceptual phase can be increased through a reduction in the predominance time of the opposing phase. We conclude that (i) MIB is a form of perceptual rivalry, and (ii) there may be a common oscillator responsible for timing aspects of all forms of perceptual rivalry.     

An information-processing model of the BOLD response in symbol manipulation tasks

Two imaging experiments were performed—one involving an algebraic transformation task studied by Anderson, Reder, and Lebiere (1996) and the other an abstraction symbol manipulation task studied by Blessing and Anderson (1996). ACT-R models exist that predict the latency patterns in these tasks. These models require activity in an imaginal buffer to represent changes to the problem representation, in a retrieval buffer to hold information from declarative memory, and in a manual buffer to hold information about motor behavior. A general theory is described about how to map activity in these buffers onto the fMRI blood oxygen level dependent (BOLD) response. This theory claims that the BOLD response is integrated over the duration that a buffer is active and can be used to predict the observed BOLD function. Activity in the imaginal buffer is shown to predict the BOLD response in a left posterior parietal region; activity in the retrieval buffer is shown to predict the BOLD response in a left prefrontal region; and activity in the manual buffer is shown to predict activity in a motor region. More generally, this article shows how to map a large class of information-processing theories (not just ACT-R) onto the BOLD response and provides a precise interpretation of the cognitive significance of the BOLD response.