Jonathan B. Freeman

MouseTracker: Software for studying real-time mental processing using a computer mouse-tracking method

In the present article, we present a software package, MouseTracker, that allows researchers to use a computer mouse-tracking method for assessing real-time processing in psychological tasks. By recording the streaming x-, y-coordinates of the computer mouse while participants move the mouse into one of multiple response alternatives, motor dynamics of the hand can reveal the time course of mental processes. MouseTracker provides researchers with fine-grained information about the real-time evolution of participant responses by sampling 60–75 times/sec the online competition between multiple response alternatives. MouseTracker allows researchers to develop and run experiments and subsequently analyze mouse trajectories in a user-interactive, graphics-based environment. Experiments may incorporate images, letter strings, and sounds. Mouse trajectories can be processed, averaged, visualized, and explored, and measures of spatial attraction/curvature, complexity, velocity, and acceleration can be computed. We describe the software and the method, and we provide details on mouse trajectory analysis. We validate the software by demonstrating the accuracy and reliability of its trajectory and reaction time data. The latest version of MouseTracker is freely available at http://mousetracker.jbfreeman.net.

A Dynamic Interactive Theory of Person Construal

A dynamic interactive theory of person construal is proposed. It assumes that the perception of other people is accomplished by a dynamical system involving continuous interaction between social categories, stereotypes, high-level cognitive states, and the low-level processing of facial, vocal, and bodily cues. This system permits lower-level sensory perception and higher-order social cognition to dynamically coordinate across multiple interactive levels of processing to give rise to stable person construals. A recurrent connectionist model of this system is described, which accounts for major findings on (a) partial parallel activation and dynamic competition in categorization and stereotyping, (b) top-down influences of high-level cognitive states and stereotype activations on categorization, (c) bottom-up category interactions due to shared perceptual features, and (d) contextual and cross-modal effects on categorization. The systems probabilistic and continuously evolving activation states permit multiple construals to be flexibly active in parallel. These activation states are also able to be tightly yoked to ongoing changes in external perceptual cues and to ongoing changes in high-level cognitive states. The implications of a rapidly adaptive, dynamic, and interactive person construal system are discussed.

Hand in Motion Reveals Mind in Motion

Recently, researchers have measured hand movements en route to choices on a screen to understand the dynamics of a broad range of psychological processes. We review this growing body of research and explain how manual action exposes the real-time unfolding of underlying cognitive processing. We describe how simple hand motions may be used to continuously index participants’ tentative commitments to different choice alternatives during the evolution of a behavioral response. As such, hand-tracking can provide unusually high-fidelity, real-time motor traces of the mind. These motor traces cast novel theoretical and empirical light onto a wide range of phenomena and serve as a potential bridge between far-reaching areas of psychological science – from language, to high-level cognition and learning, to social cognitive processes.

A neural mechanism of first impressions

Evaluating social others requires processing complex information. Nevertheless, we can rapidly form an opinion of an individual during an initial encounter. Moreover, people can vary in these opinions, even though the same information is provided. We investigated the brain mechanisms that give rise to the impressions that are formed on meeting a new person. Neuroimaging revealed that responses in the amygdala and the posterior cingulate cortex (PCC) were stronger while encoding social information that was consistent, relative to inconsistent, with subsequent evaluations. In addition, these responses scaled parametrically with the strength of evaluations. These findings provide evidence for encoding differences on the basis of subsequent evaluations, suggesting that the amygdala and PCC are important for forming first impressions.

Will a category cue attract you? Motor output reveals dynamic competition across person construal.

People use social categories to perceive others, extracting category cues to glean membership. Growing evidence for continuous dynamics in real-time cognition suggests, contrary to prevailing social psychological accounts, that person construal may involve dynamic competition between simultaneously active representations. To test this, the authors examined social categorization in real-time by streaming the x, y coordinates of hand movements as participants categorized typical and atypical faces by sex. Though judgments of atypical targets were largely accurate, online motor output exhibited a continuous spatial attraction toward the opposite sex category, indicating dynamic competition between multiple social category alternatives. The authors offer a dynamic continuity account of social categorization and provide converging evidence across categorizations of real male and female faces (containing a typical or an atypical sex-specifying cue) and categorizations of computer-generated male and female faces (with subtly morphed sex-typical or sex-atypical features). In 3 studies, online motor output revealed continuous dynamics underlying person construal, in which multiple simultaneously and partially active category representations gradually cascade into social categorical judgments. Such evidence is challenging for discrete stage-based accounts.

Race is gendered: How covarying phenotypes and stereotypes bias sex categorization

We argue that race and sex categories are psychologically and phenotypically confounded, affecting social categorizations and their efficiency. Sex categorization of faces was facilitated when the race category shared facial phenotypes or stereotypes with the correct sex category (e.g., Asian women and Black men) but was impaired when the race category shared incompatible phenotypes or stereotypes with the correct sex category (e.g., Asian men and Black women). These patterns were evident in the disambiguation of androgynous faces (Study 1) and the efficiency of judgments (Studies 1, 2, 4, and 5). These patterns emerged due to common facial phenotypes for the categories Black and men (Studies 3 and 5) and due to shared stereotypes among the categories Black and men and the categories Asian and women (Studies 4 and 5). These findings challenge the notion that social categories are perceived independent of one another and show, instead, that race is gendered.

Motions of the Hand Expose the Partial and Parallel Activation of Stereotypes

Perceivers spontaneously sort other peoples faces into social categories and activate the stereotype knowledge associated with those categories. In the work described here, participants, presented with sex-typical and sex-atypical faces (i.e., faces containing a mixture of male and female features), identified which of two gender stereotypes (one masculine and one feminine) was appropriate for the face. Meanwhile, their hand movements were measured by recording the streaming x, y coordinates of the computer mouse. As participants stereotyped sex-atypical faces, real-time motor responses exhibited a continuous spatial attraction toward the opposite-gender stereotype. These data provide evidence for the partial and parallel activation of stereotypes belonging to alternate social categories. Thus, perceptual cues of the face can trigger a graded mixture of simultaneously active stereotype knowledge tied to alternate social categories, and this mixture settles over time onto ultimate judgments.

Sexual Orientation Perception Involves Gendered Facial Cues

Perceivers can accurately judge a face’s sexual orientation, but the perceptual mechanisms mediating this remain obscure. The authors hypothesized that stereotypes casting gays and lesbians as gender “inverts,” in cultural circulation for a century and a half, lead perceivers to use gendered facial cues to infer sexual orientation. Using computer-generated faces, Study 1 showed that as two facial dimensions (shape and texture) became more gender inverted, targets were more likely to be judged as gay or lesbian. Study 2 showed that real faces appearing more gender inverted were more likely to be judged as gay or lesbian. Furthermore, the stereotypic use of gendered cues influenced the accurate judgment of sexual orientation. Although using gendered cues increased the accuracy of sexual orientation judgments overall, Study 3 showed that judgments were reliably mistaken for targets that countered stereotypes. Together, the findings demonstrate that perceivers utilize gendered facial cues to glean another’s sexual orientation, and this influences the accuracy or error of judgments.

Assessing bimodality to detect the presence of a dual cognitive process

Researchers have long sought to distinguish between single-process and dual-process cognitive phenomena, using responses such as reaction times and, more recently, hand movements. Analysis of a response distribution’s modality has been crucial in detecting the presence of dual processes, because they tend to introduce bimodal features. Rarely, however, have bimodality measures been systematically evaluated. We carried out tests of readily available bimodality measures that any researcher may easily employ: the bimodality coefficient (BC), Hartigan’s dip statistic (HDS), and the difference in Akaike’s information criterion between one-component and two-component distribution models (AICdiff). We simulated distributions containing two response populations and examined the influences of (1) the distances between populations, (2) proportions of responses, (3) the amount of positive skew present, and (4) sample size. Distance always had a stronger effect than did proportion, and the effects of proportion greatly differed across the measures. Skew biased the measures by increasing bimodality detection, in some cases leading to anomalous interactive effects. BC and HDS were generally convergent, but a number of important discrepancies were found. AICdiff was extremely sensitive to bimodality and identified nearly all distributions as bimodal. However, all measures served to detect the presence of bimodality in comparison to unimodal simulations. We provide a validation with experimental data, discuss methodological and theoretical implications, and make recommendations regarding the choice of analysis.

The neural origins of superficial and individuated judgments about ingroup and outgroup members.

We often form impressions of others based on superficial information, such as a mere glimpse of their face. Given the opportunity to get to know someone, however, our judgments are allowed to become more individuated. The neural origins of these two types of social judgment remain unknown. We used functional magnetic resonance imaging to dissociate the neural mechanisms underlying superficial and individuated judgments. Given behavioral evidence demonstrating impairments in individuating others outside ones racial group, we additionally examined whether these neural mechanisms are race‐selective. Superficial judgments recruited the amygdala. Individuated judgments engaged a cortical network implicated in mentalizing and theory of mind. One component of this mentalizing network showed selectivity to individuated judgments, but exclusively for targets of ones own race. The findings reveal the distinct—and race‐selective—neural bases of our everyday superficial and individuated judgments of others. Hum Brain Mapp, 2010.