Prenatal diagnosis, personal identity, and disability

A fascinating criticism of abortion occasioned by prenatal diagnosis of potentially disabling traits is that the complex test-and-abortion sends a morally disparaging message to people living with disabilities. I have argued that available versions of this "expressivist" argument are inadequate on two grounds. The most fundamental is that, considered as a practice, abortions prompted by prenatal testing are not semantically well-behaved enough to send any particular message; they do not function as signs in a rule-governed symbol system. Further, even granting, for the sake of argument, the expressive power of testing and aborting, it would not be possible, contra the argument's proponents, to distinguish between abortions undertaken because of beliefs about the disabling conditions the fetus might face as a child and abortions undertaken for many other possible reasons -- e.g., because of the poverty the fetus would face or the increase in family size that the birth of a new child would occasion. Here, I respond to criticisms of those arguments, and propose and defend another: the expressivist argument cannot, in general, distinguish successfully between abortion and therapy as modalities for responding to disabilities.     

The ties that bind what is known to the recall of what is new

Cued recall success varies with what people know and with what they do during an episode. This paper focuses on prior knowledge and disentangles the relative effects of 10 features of words and their relationships on cued recall. Results are reported for correlational and multiple regression analyses of data obtained from free association norms and from 29 experiments. The 10 features were only weakly correlated with each other in the norms and, with notable exceptions, in the experiments. The regression analysis indicated that forward cue-to-target strength explained the most variance, followed by backward target-to-cue strength. Target connectivity and set size explained the next most variance, along with mediated cue-to-target strength. Finally, frequency, concreteness, shared associate strength, and cue set size also contributed significantly to recall. Taken together, indices of prior word knowledge explain 49% of the recall variance. Theoretically driven equations that use free association to predict cued recall were also evaluated. Each equation was designed to condense multiple indices of word interconnectivity into a single predictor.     

Young children's use of functional information to categorize artifacts: three factors that matter

Three experiments addressed factors that might influence whether or not young children take into account function, as opposed to overall appearance or shape, when they extend the names of novel artifacts. Experiment 1 showed that 4-year-olds more often extend a name on the basis of a demonstrated function when that function provides a plausible causal account of perceptible object structure. Experiment 2 showed that they more often extend a name by function when they respond slowly, and hence thoughtfully. Experiment 3 demonstrated that they are more likely to take function into account when they extend names than when they judge similarities. Comparisons of lexical and non-lexical conditions in younger children failed to show any differences. Overall, the findings suggest that by 4 years of age, children may learn names as labels for novel artifact kinds rather than perceptual classes, and that the processes by which they categorize may be mindful and reflective, as in adults.     

Seasonal variation in human functional cerebral lateralization and free testosterone concentrations

Men have previously been reported to exhibit seasonal fluctuations on specific types of cognitive performance. It has been speculated that this performance variability is a result of changes in cerebral asymmetry due to lowered testosterone concentrations in the spring relative to the fall. In the present study, functional cerebral lateralization was measured in a group of men and women in the spring and fall. Free testosterone concentrations were assessed for participants to determine what associations might exist between seasonal variability in lateralization and seasonal fluctuations in testosterone exposure. Men and women tested in the spring exhibited exaggerated patterns of asymmetry compared to participants tested in the fall. Lower testosterone concentrations were observed in the spring compared to the fall in women, but not men. No direct associations between testosterone and lateralization were detected for either sex at either season. These results illustrate that seasonal fluctuations in testosterone exposure do not directly influence seasonal changes in functional lateralization patterns.     

Low-frequency acoustic modulations generated by the high-frequency portion of the cochlea, noninvasively recorded from the scalp of mice (Mus musculus)

Vocalizations often contain low-frequency modulations of the envelope of a high-frequency sound. The high-frequency portion of the cochlear nerve of mice (Mus musculus) generates a robust phase-locked response to these low-frequency modulations, and it can be easily recorded from the surface of the scalp. The cochlea is most sensitive to envelope modulation frequencies of approximately 500 to 2000 Hz. These responses have detection thresholds that are approximately 10 dB more sensitive than auditory brainstem responses, and they are very sharply tuned. These measurements may provide a nontraumatic means of repeatedly assessing cochlear functions involved in sound localization and perception of vocalizations.     

Modality effects and the development of the word length effect in children

Two experiments investigated the development of the word length effect in children aged 4 to 10 years, comparing auditory and visual stimuli. The question addressed was whether word length effects emerged earlier with auditory presentation or visual presentation, or whether they emerged at the same age regardless of presentation modality. Results provided evidence that word length effects emerge earlier with visual than auditory presentation. The implication of our results is that with visual presentation, 4-year-olds engage in some form of verbalization strategy that involves obtaining phonological representations of picture names and mapping them on to articulatory output plans. This strategy is clearly verbal in nature, but is not necessarily characterised as cumulative verbal rehearsal.     

Factorial structure and MMPI correlates of a fear survey schedule in a clinical population

The Wolpe-Lazarus Fear Survey Schedule was administered in a neurotic population and factor analyzed. The largest factor (Tissue Damage/Medical) was uncorrelated with either the MAS or MMPI scales. However, total Fear Survey scores and Factor II (Interpersonal) showed a similar pattern of significant positive associations with both measures. The clinical relevance of global vs. part fear survey scores is discussed.