Culture and facial expressions of emotion

With over a century of theoretical developments and empirical investigation in broad fields (e.g., anthropology, psychology, evolutionary biology), the universality of facial expressions of emotion remains a central debate in psychology. How near or far, then, is this debate from being resolved? Here, I will address this question by highlighting and synthesizing the significant advances in the field that have elevated knowledge of facial expression recognition across cultures. Specifically, I will discuss the impact of early major theoretical and empirical contributions in parallel fields and their later integration in modern research. With illustrative examples, I will show that the debate on the universality of facial expressions has arrived at a new juncture and faces a new generation of exciting questions.     

When do ratings implicate perception versus judgment? The “overgeneralization test” for top-down effects

ABSTRACT

When looking at an object—say, a banana—we can both directly perceive its visual qualities (e.g., its size) and also make higher-level judgments about its visual and non-visual properties (e.g., not only its size, but also its cost). Suppose you obtain a rating of a property such as size. Does that rating implicate seeing or merely higher-level judgment? The answer often matters a great deal -- e.g., determining whether such ratings imply “top-down” effects of cognition on perception. Too often, however, this distinction is ignored in empirical investigations of such effects. Here we suggest a simple test for when such ratings can be used to implicate perception: whenever the very same experiment “overgeneralizes” to an unambiguously non-perceptual factor, the results cannot be used to draw implications about perception, per se. As a case study, we investigate an empirical report alleging that conservatives perceive Barack Obama as darker skinned than liberals do. Two simple experiments show that the very same effects, measured via the same “representativeness” ratings, obtain with unambiguously non-perceptual and even silly factors (involving bright red horns vs. halos, rather than brightness differences). We suggest that this renders such methods unable to implicate visual processing and we recommend that “overgeneralization tests” of this type always be conducted in such contexts.     

Predicting language: MEG evidence for lexical preactivation

It is widely assumed that prediction plays a substantial role in language processing. However, despite numerous studies demonstrating that contextual information facilitates both syntactic and lexical–semantic processing, there exists no direct evidence pertaining to the neural correlates of the prediction process itself. Using magnetoencephalography (MEG), this study found that brain activity was modulated by whether or not a specific noun could be predicted, given a picture prime. Specifically, before the noun was presented, predictive contexts triggered enhanced activation in left mid-temporal cortex (implicated in lexical access), ventro-medial prefrontal cortex (previously associated with top-down processing), and visual cortex (hypothesized to index the preactivation of predicted form features), successively. This finding suggests that predictive language processing recruits a top-down network where predicted words are activated at different levels of representation, from more ‘abstract’ lexical–semantic representations in temporal cortex, all the way down to visual word form features. The same brain regions that exhibited enhanced activation for predictive contexts before the onset of the noun showed effects of congruence during the target word. To our knowledge, this study is one of the first to directly investigate the anticipatory stage of predictive language processing.     

The influence of environmental context in interpersonal observation–execution

Cyclical upper-limb movements involuntarily deviate from a primary movement direction when the actor concurrently observes incongruent biological motion. We examined whether environmental context influences such motor interference during interpersonal observation–execution. Participants executed continuous horizontal arm movements while observing congruent horizontal or incongruent curvilinear biological movements with or without the presence of an object positioned as an obstacle or distractor. When participants were observing a curvilinear movement, an object located within the movement space became an obstacle, and, thus, the curvilinear trajectory was essential to reach into horizontal space. When acting as a distractor, or with no object, the curvilinear trajectory was no longer essential. For observing horizontal movements, objects were located at the same relative locations as in the curvilinear movement condition. We found greater involuntary movement deviation when observing curvilinear than horizontal movements. Also, there was an influence of context only when observing horizontal movements, with greater deviation exhibited in the presence of a large obstacle. These findings suggest that the influence of environmental context is underpinned by the (mis-)matching of observed and executed actions as incongruent biological motion is primarily coded via bottom-up sensorimotor processes, whilst the congruent condition incorporates surrounding environmental features to modulate the bottom-up sensorimotor processes.     

Doing cognitive neuroscience: a third way

The “top-down” and “bottom-up” approaches have been thought to exhaust the possibilities for doing cognitive neuroscience. We argue that neither approach is likely to succeed in providing a theory that enables us to understand how cognition is achieved in biological creatures like ourselves. We consider a promising third way of doing cognitive neuroscience, what might be called the “neural dynamic systems” approach, that construes cognitive neuroscience as an autonomous explanatory endeavor, aiming to characterize in its own terms the states and processes responsible for brain-based cognition. We sketch the basic motivation for the approach, describe a particular version of the approach, so-called ‘Dynamic Causal Modeling’ (DCM), and consider a concrete example of DCM. This third way, we argue, has the potential to avoid the problems that afflict the other two approaches.     

Early top-down influences on bistable perception revealed by event-related potentials

A longstanding debate exists in the literature concerning bottom-up vs. top-down influences on bistable perception. Recently, a technique has been developed to measure early changes in brain activity (via ERPs) related to perceptual reversals (Kornmeier & Bach, 2004). An ERP component, the reversal negativity (RN) has been identified, and is characterized as an increase in negative potential over the posterior scalp from 150 to 350 ms for perceptual reversals compared to perceptual stability. This finding, although interesting, has not helped resolve issues related to the bottom-up vs. top-down debate because top-down influences have not been directly manipulated. The current study focused on resolving some of these issues by measuring the RN while observers maintained one of three 'intentional approaches', (1) try to reverse perception as often as possible, (2) try to stabilize perception for as long as possible, and (3) maintain a passive approach. Enhancements in RN amplitude were found for the intention-to-reverse condition compared to the passive condition. This finding suggests an early influence (150 ms) of top-down control on perceptual reversals of bistable figures. Results are discussed in terms of competing attention shifting vs. fatigue-based theories of bistable perception.     

When vaccinating against information reduction works and when it does not work

Practice not only affects how information is processed, but also which information is processed. The Information-Reduction Hypothesis (i.e. Haider & Frensch, 1996) holds that — with practice — irrelevant task information (i.e. information that is not logically needed to correctly perform the task) is discarded from processing. Recently, Gaschler and Frensch (2007) have demonstrated that Information Reduction is not affected by the frequency with which individual task configurations are presented: well-practiced and little-practiced irrelevant task configurations are discarded at the same point in time during practice; Information Reduction is thus an item-general phenomenon. These findings suggest that Information Reduction is at least in part a consequence of top-down, voluntary control. In the present research, we ask how tasks can be constructed such that Information Reduction is avoided. Our results show that item-general Information Reduction is observed even when it leads to severe processing costs (i.e. errors). On the whole, the present results are in line with models of skill acquisition incorporating top-down modulation (e.g. Haider & Frensch, 2002) and are incompatible with purely data-driven accounts of skill acquisition (e.g. Logan, 1988; Nosofski & Palmeri, 1997; Palmeri, 1997; Rickard, 2004).     

Multistable perception: when bottom-up and top-down coincide

During prolonged observation of an ambiguous figure sudden perceptual reversals occur, while the stimulus itself stays unchanged. There is a vivid debate about whether bottom-up or top-down mechanisms underlie this phenomenon. In the present study, we investigated the interrelation of two experimental factors: volitional control and discontinuous stimulus presentation. Both factors strongly modulate the rate of perceptual reversals and each is attributed either as top-down or bottom-up. We found that participants can apply specific strategies to volitionally increase and/or decrease the stability duration of each of the possible percepts according to the experimental instructions. When attempts of volitional control are combined with discontinuous stimulus presentation the effects are fully additive. Our results indicate that perceptual reversals can originate from different neural mechanisms on different time scales.     

Cognitive control of fixation duration in visual search: The role of extrafoveal processing

Participants' eye movements were monitored in two visual search experiments that manipulated target-distractor similarity (high vs. low) as well as the availability of distractors for extrafoveal processing (Free-Viewing vs. No-Preview). The influence of the target-distractor similarity by preview manipulation on the distributions of first fixation and second fixation duration was examined by using a survival analysis technique which provided precise estimates of the timing of the first discernible influence of target-distractor similarity on fixation duration. We found a significant influence of target-distractor similarity on first fixation duration in normal visual search (Free Viewing) as early as 26–28 ms from the start of fixation. In contrast, the influence of target-distractor similarity occurred much later (199–233 ms) in the No-Preview condition. The present study also documented robust and fast acting extrafoveal and foveal preview effects. Implications for models of eye-movement control and visual search are discussed.     

Self-directed speech affects visual search performance

People often talk to themselves, yet very little is known about the functions of this self-directed speech. We explore effects of self-directed speech on visual processing by using a visual search task. According to the label feedback hypothesis (Lupyan, 2007a), verbal labels can change ongoing perceptual processing—for example, actually hearing “chair” compared to simply thinking about a chair can temporarily make the visual system a better “chair detector”. Participants searched for common objects, while being sometimes asked to speak the target's name aloud. Speaking facilitated search, particularly when there was a strong association between the name and the visual target. As the discrepancy between the name and the target increased, speaking began to impair performance. Together, these results speak to the power of words to modulate ongoing visual processing.