Two classes of models for magnitude estimation

One class of models assumes that presentation of a signal results in an internal representation as a random variable. Depending on whether the signal is close to or far from the preceding signal, the variance of the representation is smaller or larger. Responses are determined largely by this random variable; however, when the signal is close to the preceding one, the response is generated by modifying the representation multiplicatively by some function of the ratio of the previous response to its representation. Power and linear functions are explored. The form of the random variable is assumed to be that arising from either the timing or the counting model operating on a Poisson process. Detailed analyses are carried out successfully only for the timing model with neural sample sizes independent of intensity; however, the data require the sample to increase with intensity. The linear response function coupled with the constant sample size counting model appears somewhat viable, but detailed calculations are very difficult to carry out. The second class of models postulates a power function relation between magnitude estimates and signals intensity for which the exponent is a Gaussian distributed random variable and the unit is the product of two log normal random variables. Again we assume an attention band such that succesive stimuli that are widely separated in intensity lead to independent samples of the random variables while a variety of assumptions is explored for successive stimuli that are near each other in intensity. Although they each give rise to the qualitative features of the data, estimates of parameters are sufficiently inconsistent that we are led to reject all of the submodels studied.     

Variability and sequential effects in cross-modality matching of area and loudness

Individual subjects' performance was examined for cross-modality matching (CMM) of loudness to visual area, as well as for magnitude estimation (ME) of the component continua. Average exponents of power functions relating response magnitude to stimulus intensity were .73 for area, .20 for loudness, and 2.44 for CMM. Predictions of the CMM exponent based on ME were higher than the empirical values, whereas more accurate predictions were made from magnitude production exponents obtained in a previous study. Sequential dependencies were assessed by comparing the response on trial n to the response on trial n--1. The coefficient of variation of the response ratio Rn/Rn-1 was systematically related to the stimulus ratio Sn/Sn-1 for both area and loudness. The coefficient was lowest for ratios near 1 and increased for larger or smaller values. For CMM, the coefficient of variation appeared to be independent of stimulus ratios. The correlation between log Rn and log Rn-1 was also related to Sn/Sn-1 for both ME and CMM. The correlation was highest when Sn/Sn-1 was 1 and dropped to 0 with increasing stimulus separation, but CMM yielded a shallower function than ME.     

Structural characteristics of clause-containing sentences and imitation by children and adults

Children of ages 4, 6, and 8 years and college students attempted to imitate sentences containing combinations of nested and self-embedded relative clauses. Asymmetries in performance predicted from extensions of previous research were obtained at all ages. The hypothesis that these differences might be attributable to two structural characteristics of clause-containing sentences was supported by correlational analyses.This report is based on a doctoral dissertation submitted to the University of Washington.     

Interestingness—A Neglected Variable in Discourse Processing

Symptomatic of a contemporary concern with affective factors in cognitive processing, a corpus of research is now emerging on the role of interestingness in discourse processing. This research has concentrated on narrative prose and has adopted a structural approach, arguing for the centrality of event and discourse structure in producing an affect like interest. The authors point out that this approach considers only one type of interest—knowledge-triggered—to the exclusion of another important type—value-triggered. A more comprehensive understanding of interest will only be achieved by researching other genres, such as exposition, and by considering the multiple sources of interest-producing conditions. We suggest the notion of “informational significance” as an inclusive term, and underline the need for a process-based understanding of interest.     

Cognitive functioning after medial frontal lobe damage including the anterior cingulate cortex: a preliminary investigation

Two patients with medial frontal lobe damage involving the anterior cingulate cortex (ACC) performed a range of cognitive tasks, including tests of executive function and anterior attention. Both patients lesions extended beyond the ACC, therefore caution needs to be exerted in ascribing observed deficits to the ACC alone. Patient performance was compared with age and education matched healthy controls. Both patients showed intact intellectual, memory, and language abilities. No clear-cut abnormalities were noted in visuoperceptual functions. Speed of information processing was mildly reduced only in Patient 2 (bilateral ACC lesion). The patients demonstrated weak or impaired performance only on selective executive function tests. Performance on anterior attention tasks was satisfactory. We tentatively suggest that our findings are inconsistent with anterior attention theories of ACC function based on neuroimaging findings. We propose that the data may imply that the ACC does not have a central role in cognition. We speculate that our findings may be compatible with the view that the ACC integrates cognitive processing with autonomic functioning to guide behaviour.     

The mini-IPIP scales: tiny-yet-effective measures of the Big Five factors of personality

The Mini-IPIP, a 20-item short form of the 50-item International Personality Item Pool-Five-Factor Model measure (Goldberg, 1999), was developed and validated across five studies. The Mini-IPIP scales, with four items per Big Five trait, had consistent and acceptable internal consistencies across five studies (= at or well above .60), similar coverage of facets as other broad Big Five measures (Study 2), and test-retest correlations that were quite similar to the parent measure across intervals of a few weeks (Study 4) and several months (Study 5). Moreover, the Mini-IPIP scales showed a comparable pattern of convergent, discriminant, and criterion-related validity (Studies 2-5) with other Big Five measures. Collectively, these results indicate that the Mini-IPIP is a psychometrically acceptable and practically useful short measure of the Big Five factors of personality.