Dispersion-weighted kappa: An integrative framework for metric and nominal scale agreement coefficients

The rater agreement literature is complicated by the fact that it must accommodate at east two different properties of rating data: the number of raters (two versus more than two) and the rating scale level (nominal versus metric). While kappa statistics are most widely used for nominal scales, intraclass correlation coefficients have been preferred for metric scales. In this paper, we suggest a dispersion-weighted kappa framework for multiple raters that integrates some important agreement statistics by using familiar dispersion indices as weights for expressing disagreement. These weights are applied to ratings identifying cells in the traditional inter-judge contingency table. Novel agreement statistics can be obtained by applying less familiar indices of dispersion in the same wayThis revised article was published online in August 2005 with the PDF paginated correctly.     

The recall of missing items

In two experiments, we studied the recall of missing items. Short lists of common words were presented once and were followed immediately by a random permutation of all but one of the presented items. The task of the subject was to recall the missing item--that is, the item present in the study set but missing from the probe set. Experiment 1 replicated the high accuracy with five-item lists originally reported by Yntema and Trask (1963) and showed that the latencies were quite short (about 750 msec). Experiment 2 varied list length unpredictably and showed that accuracy was a function of both list length (four, five, or six items) and serial position. Latency was again quite short but was essentially independent of list length and serial position. It was possible to simulate most of the effects with the power set model with no free parameters (i.e., parameters that varied with the experimental manipulations). The results seemed to be more consistent with a direct access model (the power set model of TODAM; Murdock, 1995) than with a simple search or serial-scanning model.     

Linguistic cues enhance the learning of perceptual cues

When language is correlated with regularities in the world, does it enhance the learning of these regularities? This question lies at the core of both notions of linguistic bootstrapping in children and the Whorfian hypothesis. Support for an affirmative answer is provided in an artificial-noun-learning task in which 2-year-old children were taught to distinguish categories of solid and nonsolid things with and without supporting correlated linguistic cues.     

Moments in time: metacognition, trust, and outcomes in dyadic negotiations

This research tested the relationships between turning points, cognitive and affective trust, and negotiation outcomes. After completing a simulated negotiation, participants identified turning points from videotape. Turning points were then classified as substantive (interest, offer), characterization (positive, negative), or procedural (positive, negative). Prenegotiation affective trust predicted subsequent turning points, whereas prenegotiation cognitive trust did not, suggesting that different cues influence the two types of trust. Postnegotiation cognitive trust was increased by the occurrence of interest, positive characterization, and positive procedural turning points and decreased by negative characterization turning points. Affective trust was increased by positive procedural turning points. Finally, interest turning points resulted in higher joint outcomes, whereas negative characterization turning points resulted in lower joint outcomes. We conclude that there are two paths to building trust and increasing joint gain, one through insight and one through signaling good faith intentions.     

No aging bias favoring memory for positive material: evidence from a heterogeneity-homogeneity list paradigm using emotionally toned words

Some authors argue for a memory advantage of older adults for positively toned material. To investigate the contribution of selective processing to a positivity effect, the authors investigated young (n = 72, aged 18 to 31) and older (n = 72, aged 64 to 75) adults' memory for emotionally toned words using a multitrial paradigm that compares performance for heterogeneous (mixed valence) and homogeneous (single valence) lists. Regarding the age comparison, there was no evidence for an aging bias favoring positive material. Moreover, older adults' memory was less affected by emotion-based processing prioritization. Although there was no support for age-specific processing biases in memory for emotionally toned words, the findings are consistent with proposals that negative information receives processing priority in some contexts. Possible limits to the generalizability of the present findings (e.g., to nonverbal material) are discussed.     

Psychometric properties of the Folstein Mini-Mental State Examination

Criterion-referenced (Livingston) and norm-referenced (Gilmer-Feldt) techniques were used to measure the internal consistency reliability of Folstein's Mini-Mental State Examination (MMSE) on a large sample (N = 418) of elderly medical patients. Two administration and scoring variants of the MMSE Attention and Calculation section (Serial 7s only and WORLD only) were investigated. Livingston reliability coefficients (rs) were calculated for a wide range of cutoff scores. As necessary for the calculation of the Gilmer-Feldt r, a factor analysis showed that the MMSE measures three cognitive domains. Livingston's r for the most widely used MMSE cutoff score of 24 was .803 for Serial 7s and .795 for WORLD. The Gilmer-Feldt internal consistency reliability coefficient was .764 for Serial 7s and .747 for WORLD. Item analysis showed that nearly all of the MMSE items were good discriminators, but 12 were too easy. True score confidence intervals should be applied when interpreting MMSE test scores.     

Differential induction of c-Jun and Fos-like proteins in rat hippocampus and dorsal striatum after training in two water maze tasks

Research examining the neuroanatomical bases of memory in mammals suggests that the hippocampus and dorsal striatum are parts of independent memory systems that mediate "cognitive" and stimulus-response "habit" memory, respectively. At the molecular level, increasing evidence indicates a role for immediate early gene (IEG) expression in memory formation. The present experiment examined whether acquisition of cognitive and habit memory result in differential patterns of IEG protein product expression in these two brain structures. Adult male Long-Evans rats were trained in either a hippocampal-dependent spatial water maze task, or a dorsal striatal-dependent cued water maze task. Ninety minutes after task acquisition, brains were removed and processed for immunocytochemical procedures, and the number of cells expressing Fos-like immunoreactivity (Fos-like-IR) and c-Jun-IR in sections from the dorsal hippocampus and the dorsal striatum were counted. In the dorsal hippocampus of rats trained in the spatial task, there were significantly more c-Jun-IR pyramidal cells in the CA1 and CA3 regions, relative to rats that had acquired the cued task, yoked controls (free-swim), or na?ve (home cage) rats. Relative to rats receiving cued task training and control conditions, increases in Fos-like IR were also observed in the CA1 region of rats trained in the spatial task. In rats that had acquired the cued task, patches of c-Jun-IR were observed in the posteroventral striatum; no such patches were evident in rats trained in the spatial task, yoked-control rats, or na?ve rats. The results demonstrate that IEG protein product expression is up-regulated in a task-dependent and brain structure-specific manner shortly after acquisition of cognitive and habit memory tasks.     

Toddlers recognize verbs in novel situations and sentences

Toddlers' (MA=22 and 27 months) ability to extend newly taught verbs to new situational and sentential contexts was investigated. Children were interactively taught two novel verbs, presented in only the transitive frame (e.g. You're lorping the ball), in a playroom setting. They then viewed the verb actions presented on side-by-side monitors and were asked to distinguish the verbs in three test frames (transitive, intransitive, neutral (e.g. lorping)). Both groups demonstrated learning of the verbs in the new situation and generalized the verbs to the intransitive sentence frame, but neither generalized reliably to the neutral frame. We conclude that even 22-month-olds demonstrate considerable context independence in their verb representations.