Left gaze bias in humans, rhesus monkeys and domestic dogs

While viewing faces, human adults often demonstrate a natural gaze bias towards the left visual field, that is, the right side of the viewee’s face is often inspected first and for longer periods. Using a preferential looking paradigm, we demonstrate that this bias is neither uniquely human nor limited to primates, and provide evidence to help elucidate its biological function within a broader social cognitive framework. We observed that 6-month-old infants showed a wider tendency for left gaze preference towards objects and faces of different species and orientation, while in adults the bias appears only towards upright human faces. Rhesus monkeys showed a left gaze bias towards upright human and monkey faces, but not towards inverted faces. Domestic dogs, however, only demonstrated a left gaze bias towards human faces, but not towards monkey or dog faces, nor to inanimate object images. Our findings suggest that face- and species-sensitive gaze asymmetry is more widespread in the animal kingdom than previously recognised, is not constrained by attentional or scanning bias, and could be shaped by experience to develop adaptive behavioural significance.     

Investigating naturalistic decision making in a simulated microworld: What questions should we ask?

Computer-simulated microworlds can provide a controlled method for investigating concepts related to naturalistic decision making (NDM). However, the extent to which these tools can be used to generate meaningful outcomes is unknown. The current study used a microworld called Networked Fire Chief (NFC) to explore the range of skills and knowledge acquired as participants gained practice on the program. The complexity of the NFC NDM environment was also explored. Twenty participants each completed 20 equivalent 5-min scenarios on NFC. Interview data, behavioral data and performance scores were collected across the trials. Results confirmed that NFC provides an environment that promotes appropriate perceptual-cognitive processing for NDM. However, performance improved to only a small extent across the 20 trials in four performance areas: speed, accuracy, efficiency and planning. In addition, the number of personal and situational factors to be considered when decision making on NFC was not comparable with real-world NDM environments. Overall, results indicated that the use of microworlds for research should be regulated by an understanding of the limitations of their applicability.     

Experimental effects of receiving negative weight-related feedback: a weight guessing study

The effects of receiving negative verbal weight-related feedback on the mood, self-esteem, and body image of restrained and unrestrained eaters were investigated. Female undergraduate students either reported their current weight (no feedback) or had their weight guessed as 15 lb higher than their actual weight (negative feedback) by an experimenter who presented herself as either an undergraduate (peer) or graduate student (non-peer). Participants overall had higher anxiety and felt “fatter” in the negative feedback condition. When this feedback came from a peer they felt fatter, more dissatisfied with their bodies, and, for restrained eaters, more depressed, as compared to when it came from a non-peer. These results provide empirical evidence that negative weight-related feedback produces adverse psychological consequences for young women, especially restrained eaters, and suggest the importance of peers’ perceptions of weight.     

Developmental changes in neural activity to familiar words and gestures

Infants younger than 20 months of age interpret both words and symbolic gestures as object names. Later in development words and gestures take on divergent communicative functions. Here, we examined patterns of brain activity to words and gestures in typically developing infants at 18 and 26 months of age. Event-related potentials (ERPs) were recorded during a match/mismatch task. At 18 months, an N400 mismatch effect was observed for pictures preceded by both words and gestures. At 26 months the N400 effect was limited to words. The results provide the first neurobiological evidence showing developmental changes in semantic processing of gestures.