Acoustic interaction in animal groups: signaling in noisy and social contexts

It has long been known that individuals of many species vocally communicate with one another in noisy environments and in rich contexts of social interaction. It has recently become clear that researchers interested in understanding acoustic communication in animal groups must study vocal signaling in these noisy and socially complex settings. Furthermore, recent methodological advances have made it increasingly clear that the authors can tackle these more complex questions effectively. The articles in this Special Issue stem from a Symposium held at the June 2006 meeting of the Acoustical Society of America, and illustrate some of the taxonomic and methodological diversity in studies aimed at understanding how acoustic communication functions in social grouping. This introduction to the Special Issue provides a brief overview of the articles and key ideas in this field of inquiry, and suggests some future directions to take the field to help us understand how social pressures in animal groups may influence, and be influenced by, acoustic signals.     

Malingering as a categorical or dimensional construct: the latent structure of feigned psychopathology as measured by the SIRS and MMPI-2

The 6 nonoverlapping primary scales of the Structured Interview of Reported Symptoms (SIRS) were subjected to taxometric analysis in a group of 1,211 criminal and civil examinees in order to investigate the latent structure of feigned psychopathology. Both taxometric procedures used in this study, mean above minus below a cut (MAMBAC) and maximum covariance (MAXCOV), produced dimensional results. A subgroup of participants (n = 711) with valid Minnesota Multiphasic Personality Inventory-2 (MMPI-2) protocols were included in a second round of analyses in which the 6 nonoverlapping primary scales of the SIRS and the Infrequency (F), Infrequency-Psychopathology (Fp), and Dissimulation (Ds) scales of the MMPI-2 served as indicators. Again, the results were more consistent with dimensional latent structure than with taxonic latent structure. On the basis of these findings, it is concluded that feigned psychopathology forms a dimension (levels of fabrication or exaggeration) rather than a taxon (malingering-honest dichotomy) and that malingering is a quantitative distinction rather than a qualitative one. The theoretical and clinical practice implications of these findings are discussed.     

The latent structure of anxiety sensitivity--revisited

Anxiety sensitivity has been implicated as a risk factor for the development and maintenance of panic and other anxiety disorders. Although researchers have generally assumed that anxiety sensitivity is a dimensional, rather than categorical, variable, recent taxometric research has raised questions concerning the accuracy of this assumption. The present study examined the latent structure of anxiety sensitivity by applying four taxometric procedures (MAXEIG, MAXCOV, MAMBAC, and L-Mode) to data collected from two large nonclinical samples (n = 1,025 and n = 744) using two distinct measures of anxiety sensitivity (Anxiety Sensitivity Profile and Anxiety Sensitivity Index-Revised). In contrast to previous taxometric analyses of anxiety sensitivity, results of the present research provided convergent evidence for a latent anxiety sensitivity dimension. Several potential explanations for the discrepancy between these findings and those of previous research are discussed, as well as the implications of these findings for the conceptualization and measurement of anxiety sensitivity.     

Acute ethanol ingestion impairs appetitive olfactory learning and odor discrimination in the honey bee

Invertebrates are valuable models for increasing our understanding of the effects of ethanol on the nervous system, but most studies on invertebrates and ethanol have focused on the effects of ethanol on locomotor behavior. In this work we investigate the influence of an acute dose of ethanol on appetitive olfactory learning in the honey bee (Apis mellifera), a model system for learning and memory. Adult worker honey bees were fed a range of doses (2.5%, 5%, 10%, or 25%) of ethanol and then conditioned to associate an odor with a sucrose reward using either a simple or differential conditioning paradigm. Consumption of ethanol before conditioning significantly reduced both the rate of acquisition and the asymptotic strength of the association. Honey bees also exhibited a dose dependent reduction in arousal/attention during conditioning. Consumption of ethanol after conditioning did not affect recall 24h later. The observed deficits in acquisition were not due to the affect of ethanol on gustatory sensitivity or motor function. However, honey bees given higher doses of ethanol had difficulty discriminating amongst different odors suggesting that ethanol consumption influences olfactory processing. Taken together, these results demonstrate that an acute dose of ethanol affects appetitive learning and olfactory perception in the honey bee.     

The costs of benefits: help-refusals highlight key trade-offs of social life.

Social living provides opportunities for cooperative interdependence and concomitant opportunities to obtain help from others in times of need. Nevertheless, people frequently refuse help from others, even when it would be beneficial. Decisions to accept or reject aid offers may provide a window into the adaptive trade-offs recipients make between costs and benefits in different key domains of social life. Following from evolutionary and ecological perspectives, we consider how help-recipient decision making might reflect qualitatively different threats to goal attainment within six fundamental domains of social life (coalition formation, status, self-protection, mate acquisition, mate retention, and familial care). Accepting help from another person is likely to involve very different threats and opportunities depending on which domains are currently active. This approach can generate a variety of novel empirical predictions and suggest new implications for the delivery of aid.     

Trouble crossing the bridge: altered interhemispheric communication of emotional images in anxiety

Worry is thought to involve a strategy of cognitive avoidance, in which internal verbalization acts to suppress threatening emotional imagery. This study tested the hypothesis that worry-prone individuals would exhibit patterns of between-hemisphere communication that reflect cognitive avoidance. Specifically, the hypothesis predicted slower transfer of threatening images from the left to the right hemisphere among worriers. Event-related potential (ERP) measures of interhemispheric transfer time supported this prediction. Left-to-right hemisphere transfer times for angry faces were relatively slower for individuals scoring high in self-reported worry compared with those scoring low, whereas transfer of happy and neutral faces did not differ between groups. These results suggest that altered interhemispheric communication may constitute one mechanism of cognitive avoidance in worry.     

Error detection and posterror behavior in depressed undergraduates

This study examined the influence of depression on error-monitoring and behavioral compensation after errors, two important aspects of cognitive control. Undergraduates differing in self-reported depression levels completed a modified Stroop task while error-related scalp potentials were recorded. Behaviorally, participants with higher depression scores were disproportionately slower and less accurate after errors in a task condition that included negative emotional words. Physiological results indicated that the amplitudes of the error-related negativity (ERN) and error positivity (Pe), two indices of error detection, were not correlated with depression score. ERN amplitudes predicted behavioral slowdown after errors, but only among more depressed participants in the negative-word condition. Together, the results imply that depression is associated not with an error detection deficit, but rather with alterations in subsequent performance changes, once errors have been identified.     

Examinations of identity invariance in facial expression adaptation

Faces provide a wealth of information essential to social interaction, including both static features, such as identity, and dynamic features, such as emotional state. Classic models of face perception propose separate neural-processing routes for identity and facial expression (Bruce & Young, 1986), but more recent models suggest that these routes are not independent of each other (Calder & Young, 2005). Using a perceptual adaptation paradigm in the present study, we attempted to further examine the nature of the relation between the neural representations of identity and emotional expression. In Experiment 1, adaptation to the basic emotions of anger, surprise, disgust, and fear resulted in significantly biased perception away from the adapting expression. A significantly decreased aftereffect was observed when the adapting and the test faces differed in identity. With a statistical model that separated surface texture and reflectance from underlying expression geometry, Experiment 2 showed a similar decrease in adaptation when the face stimuli had identical underlying prototypical geometry but differed in the static surface features supporting identity. These results provide evidence that expression adaptation depends on perceptual features important for identity processing and thus suggest at least partly overlapping neural processing of identity and facial expression.     

Problems for Moral Twin Earth Arguments*

Terry Horgan and Mark Timmons have recently presented a series of papers in which they argue against what has come to be called the ‘new wave’ moral realism and moral semantics of David Brink, Richard Boyd, Peter Railton, and a number of other philosophers. The central idea behind Horgan and Timmons’s criticism of these ‘new wave’ theories has been extended by Sean Holland to include the sort of realism that drops out of response-dependent accounts that make use of an analogy between moral properties and secondary qualities. This paper argues that Holland’s extension depends crucially on the fact that his target is a direct response-dependent account of moral value. His argument does not work against such accounts of more basic normative notions such as ‘harm’ or ‘benefit’. And these more basic notions may then serve as the basic normative building blocks for an indirectly response-dependent moral theory. * Thanks to Mark Timmons for helpful and friendly comments on an earlier version of this paper, and also to an audience at the 2003 Pacific APA, and to the reviewers for this journal.     

Reactive and proactive aggression: Similarities and differences

The purpose of the current study was to elaborate the nomological net surrounding the constructs of reactive (RA) and proactive aggression (PA). Typically examined in the context of children, the current study utilized a sample of 211 young adults to examine the relations between reactive and proactive aggression and measures of general personality and social information processing, as well as maladaptive behavioral correlates such as crime, substance use, and riskier sex. Both raw and residualized scores were examined. Using raw scores, the primary differences between RA and PA were related to Neuroticism (i.e., RA more strongly related) and externalizing behaviors (i.e., PA more strongly). The authors comment on the similarity of findings when using raw scores and the divergence of findings using residualized scores and argue for a cautious interpretation of differences based on residualized scores. The authors conclude that the role of Neuroticism warrants further exploration as a means for understanding the heterogeneity of aggressive behavior.