Declarative Memory

ABSTRACT— Neuroimaging of declarative memory is not an endeavor divorced from psychology but, instead, is another path through which a more complete understanding of memory has emerged. Specifically, neuroimaging allows us to determine if differences between memory states emerge from quantitatively or qualitatively distinct underlying encoding operations. Further, it has allowed for greater specification of the putative control operations adopted when we make decisions about our memories. We describe some examples of insights provided by neuroimaging into the many and varied processes that support encoding and retrieval of declarative memory.     

Age-related differences in the von restorff isolation effect

When one item is made distinct from the other items in a list, memory for the distinctive item is improved, a finding known as the isolation or von Restorff effect (after von Restorff, 1933). Although demonstrated numerous times with younger adults and children, this effect has not been found with older adults (Cimbalo & Brink, 1982). In contrast to the earlier study, we obtained a significant von Restorff effect for both younger and older adults using a physical manipulation of font colour. The effect size for older adults was smaller than that obtained for younger adults, confirming a prediction of Naveh-Benjamin's (2000) associative deficit hypothesis, which attributes age-related differences in memory performance to older adults' reduced ability to form associations. The findings are consistent with related research in which older adults demonstrate similar—but smaller—benefits for distinctive information to those for younger adults.     

Development and initial validation of public domain Basic Interest Markers

Goldberg (Goldberg, L. R. (1999). A broad-bandwidth, public-domain, personality inventory measuring the lower-level facets of several five-factor models. In: I. Mervielde, I. Deary, F. De Fruyt, & F. Ostendorf (Eds.), Personality psychology in Europe (Vol. 7, pp. 7-28). Tilburg, The Netherlands: Tilburg University Press) has argued that the commercialization of personality measures limits the range of questions investigated in empirical research. We propose that the commercialization of interest measures has had a similar effect on research in vocational psychology. Following Goldberg’s example of developing public-domain personality markers, we also propose that the development of public-domain interest markers would facilitate new directions in career-related research. The present study outlines the development and validation of a set of public-domain Basic Interest Markers (BIMs) that are freely available on a website. Using Day and Rounds’ (Day, Susan. X, & Rounds, J. (1997). A little more than kin, and less than kind: Basic interests in vocational research and career counseling. Career Development Quarterly, 45, 207-220) basic interest taxonomy, 343 items and 31 BIM scales were generated. Validity evidence is presented from correlations with the General Occupational Themes and Basic Interest Scales of the Strong Interest Inventory (Harmon, L. W., Hansen, J. C., Borgen, F. H., & Hammer, A. L. (1994). Strong Interest Inventory applications and technical guide. Stanford, CA: Stanford University Press). Discriminant validity is demonstrated by the capacity for the BIMs to differentiate major field of education or training. Implications for research and use in applied settings are discussed.     

Re-conceptualizing the past: Historical data in vocational interest research

Noteworthy progress has been made in the development of statistical models for evaluating the structure of vocational interests over the past three decades. It is proposed that historically significant interest datasets, when combined with modern structural methods of data analysis, provide an opportunity to re-examine the underlying assumptions of J.L. Holland’s [Holland, J. L. (1959). A theory of vocational choice. Journal of Counseling Psychology, 6, 35–45; Holland, J. L. (1997). Making vocational choices (3rd ed.). Odessa, FL: Psychological Assessment Resources] RIASEC model. To illustrate this potential, data obtained from J. P. Guilford’s study of interest structure were re-analyzed using modern circumplex and hierarchical clustering techniques to evaluate Holland’s and I. Gati’s [Gati, I. (1979). A hierarchical model for the structure of interests. Journal of Vocational Behavior, 15, 90–106; Gati, I. (1991). The structure of vocational interests. Psychological Bulletin, 109, 309–324] interest structures. Obtained results indicate that a circumplex model can be used to effectively represent the structure underlying Guilford’s interest measures. However, hierarchical clustering results suggest that Holland’s RIASEC types may not be the most effective categories for grouping specific interest measures into broader interest areas. The current findings provide support for the continued investigation of alternatives to Holland’s interest categories using modern measures of basic interests.     

The structure of feared social situations among individuals with a lifetime diagnosis of social anxiety disorder in two independent nationally representative mental health surveys

The present study employed both exploratory and confirmatory factor analytic approaches with nationally representative samples of individuals with a lifetime diagnosis of social anxiety disorder (n=1123; n=3091, respectively) using split-halves of the National Comorbidity Replication Survey (n=9282) and cross-validated with the Canadian Community Health Survey on Mental Health and Wellbeing (n=36,984). Strong support was found for a three-factor solution. This model was obtained from exploratory factor analysis and was further evaluated using two confirmatory factor analytic investigations in the two national samples. The three social situational domains reflected (1) Social Interaction Fears, (2) Observation Fears, and (3) Public Speaking Fears. Individuals with generalized social anxiety disorder (i.e., those who endorsed 7 or more of 13 feared social situations assessed in the survey) were significantly more likely to report Social Interaction Fears and Observation Fears compared to individuals with non-generalized social anxiety disorder (i.e., those who endorsed only 6 or fewer of 13 feared social situations). Individuals with generalized social anxiety were particularly characterized by combinations of Public Speaking Fears plus Social Interaction Fears and Observation Fears. The clinical and classification implications of our study for DSM-V are discussed.     

The discrimination of graphical elements

A model is proposed to account for how people discriminate quantities shown in pie charts and divided bar graphs (i.e. which proportion is larger, A or B?). The incremental estimation model assumes that an observer sequentially samples from the available perceptual features in a graph. The relative effectiveness of sampled perceptual features is represented by the spread of probability distributions, in the manner of signal detection theory. The model's predictions were tested in two experiments. Participants took longer with pies than divided bars and longer with non‐aligned than aligned proportions in Experiment 1. In Experiment 2, participants took longer with divided bars than pies when graphs were of unequal size. Generally, graphical formats producing longer response times incurred a greater time penalty when the difference between proportions was reduced. These results were in accordance with the model's predictions. Implications for graphical display design are discussed. Copyright © 2001 John Wiley & Sons, Ltd.     

Normative naturalism and Popperian views on reduction

Eric Scerri has argued that chemists using ab initio calculations pursue a partial reduction of chemistry to physics, while accepting that full reduction (through axiomatization) is impractical. He characterizes this view as Popperian and naturalistic. However, Popper's position on reduction is not naturalistic, as he rejected axiomatization for different reasons.     

Manipulations of irrelevant information: Suffix effects with articulatory suppression and irrelevant speech

Numerous studies have demonstrated impaired recall when the to-be-remembered information is accompanied or followed by irrelevant information. However, no current theory of immediate memory explains all three common methods of manipulating irrelevant information: requiring concurrent articulation, presenting irrelevant speech, and adding a stimulus suffix. Five experiments combined these manipulations to determine how they interact and which theoretical framework most accurately and completely accounts for the data. In Experiments 1 and 2, a list of auditory items was followed by an irrelevant speech sound (the suffix) while subjects engaged in articulatory suppression. Although articulatory suppression reduced overall recall compared to a control condition, comparable suffix effects were seen in both conditions. Experiments 3 and 4 found reliable suffix effects when list presentation was accompanied by irrelevant speech. Experiment 5 found a suffix effect even when the irrelevant speech was composed of a set of different items. Implications for working memory, pre-categorical acoustic store, the changing-state hypothesis, and the feature model are discussed.     

Mapping numerical magnitudes onto symbols: the numerical distance effect and individual differences in children's mathematics achievement

Although it is often assumed that abilities that reflect basic numerical understanding, such as numerical comparison, are related to children’s mathematical abilities, this relationship has not been tested rigorously. In addition, the extent to which symbolic and nonsymbolic number processing play differential roles in this relationship is not yet understood. To address these questions, we collected mathematics achievement measures from 6- to 8-year-olds as well as reaction times from a numerical comparison task. Using the reaction times, we calculated the size of the numerical distance effect exhibited by each child. In a correlational analysis, we found that the individual differences in the distance effect were related to mathematics achievement but not to reading achievement. This relationship was found to be specific to symbolic numerical comparison. Implications for the role of basic numerical competency and the role of accessing numerical magnitude information from Arabic numerals for the development of mathematical skills and their impairment are discussed.