Apparent haptic movement

When Os were presented with ISO-Hz vibrotactile bursts at two loci on the skin of the thigh and permitted to adjust the time between burst onsets, they reported good apparent movement between the loci. The time between stimulus onsets for optimal movement was found to vary directly with the duration of the stimulus. Replication of the experiment with electrocutaneous stimuli at 1 KHz yielded similar results. Comparison of the data with results from a study of visual apparent movement revealed no difference between the two modalities for the relationship between stimulus onset intervals and stimulus duration. The significance of the results for hypotheses about the processes underlying perception of apparent movement is discussed.     

Apparent haptic movement

When as were presented with 150-Hz vibrotactile bursts at two loci on the skin of the thigh and permitted to adjust the time between burst onsets, they reported good apparent movement between the loci. The time between stimulus onsets for optimal movement was found to vary directly with the duration of the stimulus. Replication of the experiment with electrocutaneous stimuli at 1 KHz yielded similar results. Comparison of the data with results from a study of visual apparent movement revealed no difference between the two modalities for the relationship between stimulus onset intervals and stimulus duration. The significance of the results for hypotheses about the processes underlying perception of apparent movement is discussed.     

Children at Risk: Effects of a Four-Year Head Start Transition Program on Special Education Identification

Children in Head Start are at risk for school learning or behavioral problems. While Head Start has decreased special education placement, there has been little systematic data until recently on identification of children in disability categories following preschool. In this study, two cohorts of 6,162 children across 30 sites were followed through third grade. Approximately half of these children were provided transition assistance from kindergarten through third grade. This included school transition and curricular modifications, parent involvement activities, health screening or referrals, and family social services, all similar to those received in Head Start. They were compared to a similar group of Head Start children who did not receive such services beyond the Head Start experience. Special education eligibility was determined from school records in the spring of third grade. Only 0.89% of children in the transition group were identified in the mental retardation category compared to 1.26% in the non-transition group. In the category of emotional disturbance, these same figures were 1.21% and 1.65% respectively. Both differences were statistically significant, but an opposite effect was found in the category of speech or language impairment. Findings are discussed in relation to differences in disability categories and implications for early identification.     

Observe: A multimedia course on the observational analysis of behavior

OBSERVE is a preliminary release of a multimedia course for teaching undergraduate and graduate students how and why to study behavior by direct observation. The instructional text and commentary and the self-test and examination materials are built around a series of exercises in which the student observes and categorizes film clips of the behavior of several different species in several different ways. Incorporation of elements from The Observer software for computer recording and video analysis implements fully computerized continuous recording. At present, the text, together with check sheets that the program generates, enables a comparison between one-zero, instantaneous, and continuous sampling of the same behavioral excerpts. Matrices are printed out for an exercise in calculating interobserver reliability. Another section supports carrying out and writing up a small observational project on human behavior in the field. Plans for the future development of OBSERVE are briefly described.     

Promises beyond assurance

Breaking a promise is generally taken to involve committing a certain kind of moral wrong, but what (if anything) explains this wrong? According to one influential theory that has been championed most recently by Scanlon, the wrong involved in breaking a promise is a matter of violating an obligation that one incurs to a promisee in virtue of giving her assurance that one will perform or refrain from performing certain acts. In this paper, we argue that the “Assurance View”, as we call it, is susceptible to two kinds of counterexamples. The first show that giving assurance is not sufficient for incurring the kind of obligation of fulfillment that one violates in breaking a promise. The second show that giving assurance is not necessary. Having shown that the Assurance View fails in these ways, we then very briefly sketch the outline of what we take to be a better view—a view that we claim is not only attractive in its own right and that avoids the earlier counterexamples, but that also affords us a deeper explanation of why the Assurance View seems initially plausible, yet nonetheless turns out to be ultimately inadequate.     

Hemispheric connectivity and the visual–spatial divergent-thinking component of creativity

Background/hypothesis

Divergent thinking is an important measurable component of creativity. This study tested the postulate that divergent thinking depends on large distributed inter- and intra-hemispheric networks. Although preliminary evidence supports increased brain connectivity during divergent thinking, the neural correlates of this characteristic have not been entirely specified. It was predicted that visuospatial divergent thinking would correlate with right hemisphere white matter volume (WMV) and with the size of the corpus callosum (CC).

Methods

Volumetric magnetic resonance imaging (MRI) analyses and the Torrance Tests of Creative Thinking (TTCT) were completed among 21 normal right-handed adult males.

Results

TTCT scores correlated negatively with the size of the CC and were not correlated with right or, incidentally, left WMV.

Conclusions

Although these results were not predicted, perhaps, as suggested by Bogen and Bogen (1988), decreased callosal connectivity enhances hemispheric specialization, which benefits the incubation of ideas that are critical for the divergent-thinking component of creativity, and it is the momentary inhibition of this hemispheric independence that accounts for the illumination that is part of the innovative stage of creativity. Alternatively, decreased CC size may reflect more selective developmental pruning, thereby facilitating efficient functional connectivity.     

Inhibitory and facilitatory location priming in patients with left-sided visual hemi-neglect

In visual search for pop-out targets, reaction times are facilitated when the target on the current trial appears at a previous target location, and inhibited when it appears at a previous distractor location, relative to when it appears at a previously empty (neutral) location (Maljkovic and Nakayama, Perception and Psychophysics 58:977–991, 1996). However, while normal subjects are able to positively/negatively tag selected target/rejected distractor locations to guide search on the next trial, patients with visual hemi-neglect may have a (uni- or bilateral) deficit in these functions that may contribute to their disturbed visual scanning behavior. To examine this, using a pop-out search task, the present study assessed cross-trial facilitatory and inhibitory priming in 14 patients with left-sided visual hemi-neglect and in 14 age-, education-, and IQ-matched control subjects. The group of neglect patients did show significant facilitatory and inhibitory priming. However, while control subjects exhibited balanced effects of facilitation and inhibition, inhibition was relatively reduced in magnitude in neglect patients. In particular, inhibition was virtually absent in two patients with lesions affecting superior regions of the frontal cortex, putatively encroaching on the frontal eye field of the right hemisphere. These findings provide neuropsychological evidence that facilitatory and inhibitory priming effects are based on dissociable mechanisms, consistent with Geyer et al. (Journal of Experimental Psychology: Human Perception and Performance 33:788–797, 2007).