Lack of association of computer use and ability with spontaneous mental visualization

Relationships between frequency of computer use or ability to use the computer effectively with the tendency to construct and process visual mental images were investigated by administering a computer-use questionnaire and a visualization questionnaire to a sample of 185 Italian and Spanish undergraduates. Analysis did not support associations between either (a) frequent computer use of any kind or (b) high competence in using the computer for various purposes and spontaneous use of imagery.     

A reversal in the direction of detection asymmetry: effects of spatial density,spatial regularity,and retinal eccentricity

We analyzed detection asymmetry, using openand closed squares as target and contextelements. It was found that varying density, regularity, and target eccentricity not only can modulate the amount of asymmetry, but also can produce a reversal in the direction of the asymmetry. The results suggest that the different stimuli are processed with different grains of analysis,consisting of in some cases, single elements and their properties and, in other cases, larger units of the stimulus array and more globalproperties. A detection task that can utilize the properties that are available with a given grain of analysis would show an advantage over a task for which the given grain of analysis is not as favorable, resulting indetection asymmetry in one direction or another.     

Causal conditional reasoning and semantic memory retrieval: a test of the semantic memory framework

This study tested and refined a framework that proposes a mechanism for retrieving alternative causes and disabling conditions (Cummins, 1995) during reasoning. Experiment 1 examined the relation between different factors affecting retrieval. The test revealed high correlations between the number of possible alternative causes or disabling conditions and their strength of association and plausibility. Experiment 2 explored the hypothesis that due to a more extended search process, conditional inferences would last longer when many alternative causes or disabling conditions were available. Affirmation of the consequent (AC) and modus ponens (MP) latencies showed the hypothesized pattern. Denial of the antecedent (DA) and modus tollens (MT) inferences did not show latency effects. The experiment also identified an effect of the number of disabling conditions on AC and DA acceptance. Experiment 3 measured efficiency of disabler retrieval by a limited time, disabler generation task. As predicted, better disabler retrieval was related to lower acceptance of the MP and MT inferences.     

HMOs and physician conflicts of interest

In a recent issue of this journal, Francis Beckwith's "The Ethics of Referral Kickbacks and Self-Referral and the HMO Physician as Gatekeeper: An Ethical Analysis" provided an admirably provocative defense of the claim that Health Maintenance Organization (HMO) physician gatekeepers are morally indistinguishable from physician referral kickbacks and self-referrals. Here I will argue that Beckwith's defense is weak. I will also make some tentative suggestions about approaching the issue of physician conflicts of interest.     

Auditory verb recognition in developmental language impairment

This research addresses the issues of frequency and regularity in auditory verb recognition and their importance for the organization of the mental lexicon in DLI francophones. A primed auditory lexical decision task probes reaction times and response accuracy in DLI and control participants on frequent and infrequent, and regular and irregular, inflected forms of verbs. Results show no priming for inflectionally related forms as well as strong frequency effects in DLI participants. These findings lend additional support to the hypothesis that developmental language impairment is a deficit in lexical representation.     

Effects of right and left hemisphere damage on performance of the "Right Hemisphere Communication Battery"

A Hebrew adaptation of Gardner and Brownell's (1986) "Right Hemisphere Communication Battery" (HRHCB) was administered to 27 right brain-damaged (RBD) patients, 31 left brain-damaged (LBD) patients, and 21 age-matched normal controls. Both patient groups showed deficits relative to controls and overall there was no difference between the two patient groups. A factor analysis of patients' scores on the HRHCB yielded two interpretable factors, a verbal and a nonverbal one. These factors were not lateralized. Performance of patients on the HRHCB correlated significantly and positively with performance on most tests of basic language functions, measured with a Hebrew adaptation of the "Western Aphasia Battery" (HWAB) and with other cognitive functions measured with standardized neuropsychological tests. There were stronger correlations of HRHCB with subtests of the HWAB in LBD patients and with nonlanguage cognitive tests in RBD patients. In the LBD group, HRHCB subtests' scores correlated negatively with lesion extent in frontal and temporal perisylvian regions. Such localization was not observed in RBD patients. The results argue against selective right hemisphere (RH) involvement in the RHCB, alleged to measure pragmatic aspects of language use, and show, instead, bilateral involvement. The results also argue against a modular organization of these functions of language use, especially in the RH.     

Is phonological information mapped onto semantic information in a one-to-one manner?

Spoken word recognition models have to explain the influence of mismatching information on lexical activation. The effect of mismatching information is usually addressed with cross-modal semantic priming experiments using priming effects as a measure of the degree of lexical activation. Pseudowords phonologically related to a semantic associate of the target, e.g., *domato-PAPRIKA, serve as primes. Mismatch effects at the word form level are supposed to percolate unaltered to the semantic level. We show that cross-modal semantic priming might underestimate activation at the word form level. Targets (e.g., PAPRIKA) were preceded by either phonologically related pseudoword primes (e.g., *baprika) or semantically related pseudoword primes (e.g., *domato). Different priming and RT patterns were obtained for the two priming relations.     

Prognostic relevance of quantitative topographical EEG in patients with poststroke aphasia

In this prospective study we analyzed the prognostic value of topographical quantitative EEG (qEEG) in poststroke aphasia. Twenty-three right-handed patients (ages 56 +/- 12 years) with different types of aphasia were studied. Quantitative EEG under resting conditions and an aphasia test battery were applied twice, 2 and 8 weeks after a stroke. EEG power fast Fourier transform was performed for delta (2-3.5 Hz), theta (4-7.5 Hz), alpha (8-13 Hz), and beta (13.5-20 Hz) frequency bands. EEG abnormalities within and outside speech relevant areas are related to restitution of poststroke aphasia. In the ischemic regions they indicate local disturbances; outside they reflect failures in neuronal networks involved in the generation and propagation of the alpha rhythm.