How does cognition evolve? Phylogenetic comparative psychology

Now more than ever animal studies have the potential to test hypotheses regarding how cognition evolves. Comparative psychologists have developed new techniques to probe the cognitive mechanisms underlying animal behavior, and they have become increasingly skillful at adapting methodologies to test multiple species. Meanwhile, evolutionary biologists have generated quantitative approaches to investigate the phylogenetic distribution and function of phenotypic traits, including cognition. In particular, phylogenetic methods can quantitatively (1) test whether specific cognitive abilities are correlated with life history (e.g., lifespan), morphology (e.g., brain size), or socio-ecological variables (e.g., social system), (2) measure how strongly phylogenetic relatedness predicts the distribution of cognitive skills across species, and (3) estimate the ancestral state of a given cognitive trait using measures of cognitive performance from extant species. Phylogenetic methods can also be used to guide the selection of species comparisons that offer the strongest tests of a priori predictions of cognitive evolutionary hypotheses (i.e., phylogenetic targeting). Here, we explain how an integration of comparative psychology and evolutionary biology will answer a host of questions regarding the phylogenetic distribution and history of cognitive traits, as well as the evolutionary processes that drove their evolution.     

A Connectionist Model of Phonological Representation in Speech Perception

A number of recent studies have examined the effects of phonological variation on the perception of speech. These studies show that both the lexical representations of words and the mechanisms of lexical access are organized so that natural, systematic variation is tolerated by the perceptual system, while a general intolerance of random deviation is maintained. Lexical abstraction distinguishes between phonetic features that form the invariant core of a word and those that are susceptible to variation. Phonological inference relies on the context of surface changes to retrieve the underlying phonological form. In this article we present a model of these processes in speech perception, based on connectionist learning techniques. A simple recurrent network was trained on the mapping from the variant surface form of speech to the underlying form. Once trained, the network exhibited features of both abstraction and inference in its processing of normal speech, and predicted that similar behavior will be found in the perception of nonsense words. This prediction was confirmed in subsequent research (Gaskell & Marslen-Wilson, 1994).     

A multigroup item response theory analysis of the psychopathy checklist--revised

Item response theory was used to investigate the functioning of the Psychopathy Checklist-Revised (PCL-R; R. D. Hare, 1991, 2003) in several offender populations. With male criminal offenders (N=3,847) as a reference group, differential item functioning analyses were performed for 3 comparison groups: female criminal offenders (N=1,219), male forensic psychiatric patients (N=1,246), and male criminal offenders scored from file reviews (N=2,626). Results are discussed in the context of the 2-factor, 4-facet model for the PCL-R (R. D. Hare, 2003; J. Parker, G. Sitarenios, & R. D. Hare, 2003). Application of a multigroup graded response model to all 4 groups suggests scalar equivalence may hold at least approximately for each population, although the PCL-R provided slightly greater information about the latent trait of psychopathy for male criminal offenders scored from the standard procedure.     

'Unwilling' versus 'unable': chimpanzees' understanding of human intentional action

Understanding the intentional actions of others is a fundamental part of human social cognition and behavior. An important question is therefore whether other animal species, especially our nearest relatives the chimpanzees, also understand the intentional actions of others. Here we show that chimpanzees spontaneously (without training) behave differently depending on whether a human is unwilling or unable to give them food Chimpanzees produced more behaviors and left the testing station earlier with an unwilling compared to an unable (but willing) experimenter These data together with other recent studies on chimpanzees' knowledge about others' visual perception show that chimpanzees know more about the intentional actions and perceptions of others than previously demonstrated     

ERP responses to images of abstract artworks,photographs of natural scenes,and artificially created uncomfortable images

The idea of efficient coding in the visual brain allows for predictions for the processing of various types of images, including certain artworks, natural images and uncomfortable images. Efficient processing is thought to result in lower responses compared to less efficient processing. The efficiency of the processing is suggested to depend on the architecture of the visual system and the properties of the input image. In this study, neural responses were estimated using EEG across the categories of a set of five images of abstract artworks, a set of five photographs of natural images and a set of five computer-generated uncomfortable images. EEG responses to contrast-matched images were found to be lower for the set of five abstract artworks used in the study compared to the set of photographs of natural images, lending preliminary support for the idea that certain abstract artworks, for example the work of Pollock, may be processed efficiently.     

The super-ordinate nature of the psychopathy checklist-revised

Psychopathy, while perhaps the earliest and most recognized personality disorder, is the subject of intense debate about its nature and measurement. The most recent proposal on its structural nature suggests that it is a multifaceted construct, made up of at least four dimensions reflecting Interpersonal, Affective, Lifestyle, and Antisocial anomalies (Hare & Neumann, 2005, 2006). These dimensions are significantly interrelated, suggesting that they are indicators for a super-ordinate factor. The nature of this higher-order factor may reflect the unifying feature which comprehensively defines the disorder. To examine this super-factor, the current study used several very large data sets of male (N = 4865) and female (N = 1099) offenders, and forensic psychiatric patients (N = 965), who were assessed with the Psychopathy Checklist-Revised (PCL-R; Hare, 2003). Structural equation modeling results indicated that the four first-order factor dimensions could be explained by a single second-order cohesive super-factor.     

A taxometric analysis of the latent structure of psychopathy: evidence for dimensionality

The taxonomic status of psychopathy is controversial. Whereas some studies have found evidence that psychopathy, at least its antisocial component, is distributed as a taxon, others have found that both major components of psychopathy-callousness/unemotionality and impulsivity/antisocial behavior-appear to distribute as dimensions and show little evidence of taxonicity. In the present study, recent advances in taxometric analysis were added to P. Meehl's (1995) multiple consistency tests strategy for assessing taxonicity, and they were applied to Psychopathy Checklist-Revised (R. D. Hare, 2003) ratings of 4,865 offenders sampled from multiple forensic settings. The results indicated that both the individual components of psychopathy and their interface are distributed dimensionally. Both the implications of these results for research in psychopathy and the integration of these findings with previous taxometric studies of psychopathy are discussed.     

Estimating the heritability of cognitive traits across dog breeds reveals highly heritable inhibitory control and communication factors

Animal Cognition - Trait heritability is necessary for evolution by both natural and artificial selection, yet we know little about the heritability of cognitive traits. Domestic dogs are a...