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.     

Just lying there, remembering: improving recall of prose in amnesic patients with mild cognitive impairment by minimising interference

The hallmark of amnesia is poor explicit long-term memory along with normal short-term memory. It is often stated that information encountered by amnesic patients is forgotten within 1 minute of presentation. However, previous work has not distinguished between forgetting as a function of time versus the interfering material occupying that time. We show that there is a marked benefit of reduced interference in amnesic patients with mild cognitive impairment (MCI), a condition that is characterised by anterograde amnesia in the absence of other neuropsychological deficits and carries an increased risk for Alzheimer's disease. The result suggests that long-term memory is encoded in these patients to a greater extent than had been realised but that their memory is highly vulnerable to interference.     

Coherence of the irrelevant-sound effect: Individual profiles of short-term memory and susceptibility to task-irrelevant materials

We examined individual and developmental differences in the disruptive effects of irrelevant sounds on serial recall of printed lists. In Experiment 1, we examined adults (N = 205) receiving eight-item lists to be recalled. Although their susceptibility to disruption of recall by irrelevant sounds was only slightly related to memory span, regression analyses documented highly reliable individual differences in this susceptibility across speech and tone distractors, even with variance from span level removed. In Experiment 2, we examined adults (n = 64) and 8-year-old children (n = 63) receiving lists of a length equal to a predetermined span and one item shorter (span-1). We again found significant relationships between measures of span and susceptibility to irrelevant sounds, although in only two of the measures. We conclude that some of the cognitive processes helpful in performing a span task may not be beneficial in the presence of irrelevant sounds.