Evolutionary perspectives on imitation: is a comparative psychology of social learning possible?

Studies of imitation in animals have become numerous in recent times, but do they contribute to a comparative psychology of social learning? We review this burgeoning field to identify the problems and prospects for such a goal. Difficulties of two main kinds are identified. First, researchers have tackled questions about social learning from at least three very different theoretical perspectives, the "phylogenetic", "animal model", and "adaptational". We examine the conflicts between them and consider the scope for integration. A second difficulty arises in the methodological approaches used in the discipline. In relation to one of these - survey reviews of published studies - we tabulate and compare the contrasting conclusions of nine articles that together review 36 studies. The basis for authors' disagreements, including the matters of perceptual opacity, novelty, sequential structure, and goal representation, are examined. In relation to the other key method, comparative experimentation, we identify 12 studies that have explicitly compared species' imitative ability on similar tasks. We examine the principal problems of comparing like with like in these studies and consider solutions, the most powerful of which we propose to be the use of a systematic range of task designs, rather than any single "gold standard" task.     

Validation of the dimensional factor structure of the personality psychopathology five in clinical and nonclinical samples

Confirmatory factor analysis (CFA) was used to determine whether the latent structure underlying the items composing the MMPI-2 Personality Psychopathology Five scales (PSY-5; Harkness, McNulty, & Ben-Porath, 1995) is representative of the theoretical model that informed their construction. Results from the CFA revealed a good fit between the hypothesized five-factor model and the obtained latent factor structure in both clinical (n = 284) and nonclinical (n = 351) samples. Moreover, the PSY-5 model proved to be a better fit than a random five-factor model and a one-factor model. Correlations between the PSY-5 scales and a set of MMPI-2 (DSM-IV) personality disorder scales provided additional evidence of convergent and discriminant validity.     

Perceived dysfunction of male-typed and female-typed DSM-IV personality disorder criteria

To determine whether female-typed personality disorders are associated with a different pattern of dysfunction than male-typed disorders, lay judges (N = 216) estimated the amount of social impairment, occupational impairment, and personal distress related to symptoms of personality disorders. Results for both the subset of six disorders originally rated by clinician judges in the research of Funtowicz and Widiger (1999) and for a larger set of nine disorders revealed a pattern originally reported by Funtowicz and Widiger where female-typed disorders were associated with relatively higher ratings of personal distress, whereas male-typed disorders were associated with relatively higher ratings of social (and sometimes occupational) impairment. Findings are discussed with respect to the emphasis of different forms of dysfunction for male- and female-typed disorders, lay versus clinician judgments, and directions for future research.     

A computational model of anterior cingulate function in speeded response tasks: effects of frequency,sequence, and conflict

A growing body of evidence from functional neuroimaging and computational modeling studies indicates that the anterior cingulate cortex (ACC) detects the presence of response conflict and conveys this information to other brain regions, enabling subsequent adjustments in cognitive control. The present study examined previous empirical findings of increased ACC for low-frequency stimuli across three distinct speeded response tasks (two-alternative forced choice, go/no-go, and oddball). Simulations conducted in a neural network model incorporating sequential priming mechanisms (developed in Cho et al., 2002) confirmed that a computational measure of response conflict was higher on low-frequency trials across all three tasks. In addition, the model captured detailed aspects of behavioral reaction time and accuracy data, predicted the dynamics of ACC activity related to trial sequence effects, and provided evidence for the functional role of conflict information in performance monitoring and optimization. The results indicate that the conflict-monitoring hypothesis, augmented by mechanisms for encoding stimulus history, can explain key phenomena associated with performance in sequential speeded response tasks.     

The effect of specific test queries on source-monitoring event-related potentials

Source-monitoring decision processes were manipulated during retrieval while event-related potentials (ERPs) were recorded. Words were either seen or heard at study, and memory for modality was measured on two separate yes-no source tests. Decision processes were varied across the two tests by asking participants to respond to leading questions. One leading question asked if the items were seen at study, whereas the second question asked if the items were heard at study (cf., Marsh & Hicks, 1998). Behavioral responses indicated that leading questions altered the way in which memory was evaluated to determine the source of information. Varying the decision processes affected frontal--but not parietal ERPs--indicating that frontal ERPs reflect processing that is used to evaluate activated information. Furthermore, left and right frontal ERP activity was affected by the combination of test query and type of source supporting the hypothesis that both the right and left frontal lobes contribute to memory retrieval processes. The pattern of frontal ERP effects supports the hypothesis that activation in right frontal areas reflect basic decision processes that are used to determine source and that the left frontal lobes are recruited when more systematic processing is required by the test context (cf., Nolde, Johnson, & Raye, 1998b).     

The hippocampus and memory of verbal and pictorial material

Recognition of words and kaleidoscope pictures showed a double dissociation of left and right hippocampal activity using magnetic source imaging (MSI). MSI has advantages over alternative imaging techniques that measure hemodynamic changes for identifying regional changes in brain activity in real time and on an individual subject basis without the need for image subtraction. In this study, lists of words or kaleidoscope pictures were presented for memorization followed by tests of list items and foils during which brain activity was recorded. There was greater activation in the left than the right hippocampus with abstract nouns (e.g., relief) and greater activation in the right than the left hippocampus with kaleidoscope pictures. This dissociation was evident on a case by case basis. This study demonstrates the specialization of the two medial temporal lobe (MTL) regions, including the hippocampi, for mnemonic processing of verbal and pictorial items that are difficult to encode verbally.     

Pettit on Consequentialism and Universalizability

Philip Pettit has argued that universalizability entails consequentialism. I criticise the argument for relying on a question-begging reading of the impartiality of universalization. A revised form of the argument can be constructed by relying on preference-satisfaction rationality, rather than on impartiality. But this revised argument succumbs to an ambiguity in the notion of a preference (or desire). I compare the revised argument to an earlier argument of Pettit’s for consequentialism that appealed to the theoretical virtue of simplicity, and I raise questions about the force of appeal to notions like simplicity and rationality in moral argument.     

Emotion-modulated performance and activity in left dorsolateral prefrontal cortex

Functional MRI (fMRI) was used to examine the relationship between processing of pleasant and unpleasant stimuli and activity in prefrontal cortex. Twenty volunteers identified the colors in which pleasant, neutral, and unpleasant words were printed. Pleasant words prompted more activity bilaterally in dorsolateral prefrontal cortex (DLPFC) than did unpleasant words. In addition, pleasant words prompted more activity in left than in right DLPFC. Response speed to pleasant words was correlated with DLPFC activity. These data directly link positive affect, enhanced performance, and prefrontal activity, providing some of the first fMRI evidence supporting models of emotional valence and frontal brain asymmetry based on electroencephalography (EEG).     

Correlates of compassion fatigue and burnout in chaplains and other clergy who responded to the September 11th attacks in New York City

Participants at a June 2002 conference about the September 11th attacks were tested for compassion fatigue, compassion satisfaction, and burnout. The sample consisted of 343 clergy, including 97 chaplains. A total of 149 (43.4%) of the participants had responded as disaster-relief workers following the September 11th attacks. The number of hours clergy worked with trauma victims each week was directly related to compassion fatigue among responders and non-responders. Compassion fatigue also was positively related to the number of days that responders worked at Ground Zero, while disaster-relief work with the American Red Cross reduced compassion fatigue and burnout. Clinical Pastoral Education tended to decrease compassion fatigue and burnout and increase compassion satisfaction in both responders and non-responders. Burnout was inversely related to age in both groups.     

The development of gaze following and its relation to language

We examined the ontogeny of gaze following by testing infants at 9, 10 and 11 months of age. Infants (N = 96) watched as an adult turned her head toward a target with either open or closed eyes. The 10- and 11-month-olds followed adult turns significantly more often in the open-eyes than the closed-eyes condition, but the 9-month-olds did not respond differentially. Although 9-month-olds may view others as 'body orienters', older infants begin to register whether others are 'visually connected' to the external world and, hence, understand adult looking in a new way. Results also showed a strong positive correlation between gaze-following behavior at 10-11 months and subsequent language scores at 18 months. Implications for social cognition are discussed in light of the developmental shift in gaze following between 9 and 11 months of age.