Emergence of Life

Discussions of the origin of life usually assume that there is a specific event, however improbable, by which dead matter became a living entity. Naturalistic accounts, although in seeming opposition to theistic explanations of the apparent design of even the simplest cells, often share the assumption that there is a specific line to be crossed. If the problem is recast as one of a process of emergence of biochemistry from protobiochemistry, which in turn emerged from the organic chemistry and geochemistry of primitive earth, the resources of the new sciences of complex systems dynamics can provide a more robust conceptual framework within which to explore the possible pathways of chemical complexification leading to life. In such a view the emergence of life is the result of deep natural laws (the outlines of which we are only beginning to perceive) and reflects a degree of holism in those systems that led to life. Further, there is the possibility of developing a more general theory of biology and of natural organization from such an approach. The emergence of life may thus be seen as an instance of the broader innate creativity of nature and consistent with a possible natural teleology.     

Capacity to vary writing hand/posture in relation to the Levy and Reid model for control of writing

Inherent in Levy and Reid's (1978) neurological model for the control of writing hand/posture were implications pertaining to the capacity of people to vary their hand/posture when writing. These implications were formulated into the writing variation hypothesis. The skill with which right-normal, left-inverted, and left-normal writers were able to write using hand/postures other than their preferred one was examined. The resulting performance was incompatible with Levy and Reid's neurological model. Whether or not subjects wrote with their preferred hand seemed more important than which posture they used.     

Journal of experimental psychology: human perception and performance

We examined the nonveridicality of visual direction produced by monocular viewing. In Experiment 1, 19 subjects pointed to a small light and moved a small light to their subjective median plane. The extent of constant error under monocular and binocular viewing conditions differed in both tasks (p less than .001). The monocular-binocular difference was larger when the viewing distance was 25 cm than when it was 50 cm (p less than .01). Also, correlations between phoria and monocular-binocular differences ranged from .58 to .77, depending on viewing distances and tasks. The effects of phoria within the context of Hering's .001). The monocular-binocular difference was larger when the viewing distance was 25 cm than when it was 50 cm (p less than .01). Also, correlations between phoria and monocular-binocular differences ranged from .58 to .77, depending on viewing distances and tasks. The effects of phoria within the context of Hering's .001). The monocular-binocular difference was larger when the viewing distance was 25 cm than when it was 50 cm (p less than .01). Also, correlations between phoria and monocular-binocular differences ranged from .58 to .77, depending on viewing distances and tasks. The effects of phoria within the context of Hering's principle of visual direction can account for these results. In Experiment 2, the same subjects adapted to phoria-induced error by placing a finger over a monocularly viewed target. The difference in their pointing responses before and after the task were reliable (p less than .005), and the correlations between phoria and the pre- to posttest differences were .45 and .77, depending on the number of adaptation trials. We argue that all monocular experiments dealing with visual direction should control for these effects.     

Detection in a four-observation two-channel task

Two models are proposed for a four-observation two-channel forced-choice paradigm of signal detection. The first model, an extension of signal detection theory, fails, while the second model, an extension of the classical decision threshold model, succeeds.     

Attention bands in absolute identification

If both the number of one-dimensional signals and their range are sufficiently large (about 7 and 20 dB for loudness), the information transmitted in absolute identification is not much increased by increasing either variable (Miller, 1956; Braida & Durlach, 1972). The data can be represented in terms of Thurstonian discriminal dispersions in which the variance is proportional to the square of the signal range in decibels (Durlach & Braida, 1969; Gravetter & Lockhead, 1973), but it is by no means obvious what sorts of mechanisms would lead to this model. An alternative is proposed, namely, that there is a roving attention band, about 10 to 15 dB wide, such that signals falling within the band are represented by a sensory sample size about an order ot magnitude larger than when the same signal falls outside the band. With reasonable choices for parameters, including the subjective continuum growing as a power function of intensity with an exponent about 3, this nicely accounts for the data. In an attempt to examine the change of performance with range, we replicated the BraidaoDurlach experiment with many additional points. These data are not, however, adequate to decide between the two models.     

What Right to Die?

This letter first discusses two meanings of a "right to die." In the popular sense, the term refers to a right to refuse life-sustaining treatment. In the strict sense, the term signifies an affirmative right to obtain death--a right to suicide. The letter then explores the legal implications of a suicide right. This right would extend to competent adults, mature minors, and probably also incompetent persons. Counselors would have to inform clients of the suicide option. Intervention to prevent suicide could trigger civil liability. Suicidal intentions would not justify involuntary commitment. Consent would become a defense to homicide.     

Lexical selection in bilingual speech production does not involve language suppression

The "hard problem" in bilingual lexical access arises when translation-equivalent lexical representations are activated to roughly equal levels and, thus, compete equally for lexical selection. The language suppression hypothesis (D. W. Green, 1998) solves this hard problem through the suppression of lexical representations in the nontarget language. Following from this proposal is the prediction that lexical selection should take longer on a language switch trial because the to-be-selected representation was just suppressed on the previous trial. Inconsistent with this prediction, participants took no longer to name pictures in their dominant language on language switch trials than they did on nonswitch trials. These findings indicate that nontarget lexical representations are not suppressed. The authors suggest that these results undermine the viability of the language suppression hypothesis as a possible solution to the hard problem in bilingual lexical access.