The implications of low quality bicycle paths on gaze behavior of cyclists: A field test

Unlike for car driving and walking, the visual behavior during cycling is poorly documented. The aim of this experiment was to explore the visual behavior of adult bicycle users ‘in situ’ and to investigate to what extent the surface quality affects this behavior. Therefore cycling speed, gaze distribution and gaze location of five participants were analyzed on a high and a low quality bicycle track. Although there was no difference in cycling speed between the low and the high quality cycling path, there was an apparent shift of attention from distant environmental regions to more proximate road properties on the low quality track. These findings suggest that low quality bicycle tracks may affect the alertness and responsiveness of cyclists to environmental hazards.     

Use of experimenter-given cues in dogs

Since the observations of O. Pfungst the use of human-provided cues by animals has been well-known in the behavioural sciences (“Clever Hans effect”). It has recently been shown that rhesus monkeys (Macaca mulatta) are unable to use the direction of gazing by the experimenter as a cue for finding food, although after some training they learned to respond to pointing by hand. Direction of gaze is used by chimpanzees, however. Dogs (Canis familiaris) are believed to be sensitive to human gestural communication but their ability has never been formally tested. In three experiments we examined whether dogs can respond to cues given by humans. We found that dogs are able to utilize pointing, bowing, nodding, head-turning and glancing gestures of humans as cues for finding hidden food. Dogs were also able to generalize from one person (owner) to another familiar person (experimenter) in using the same gestures as cues. Baseline trials were run to test the possibility that odour cues alone could be responsible for the dogs’ performance. During training individual performance showed limited variability, probably because some dogs already “knew” some of the cues from their earlier experiences with humans. We suggest that the phenomenon of dogs responding to cues given by humans is better analysed as a case of interspecific communication than in terms of discrimination learning. Received: 30 May 1998 / Accepted after revision: 6 September 1998     

Weigh(t)ing for Awareness

We wished to learn if weight perception can be extinguished by studying two patients with right hemisphere brain damage. When lifting weights simultaneously, a patient with right frontal damage was not biased in her judgments of which weight was heavier. By contrast, a patient with right parietal damage reported left-sided weights as being lighter than those on the right. Psychophysical power functions revealed that her awareness of increasing weights on the left was dampened compared to the right when lifting weights individually on each side. Strikingly, her awareness of weight changes on the left was completely abolished when she lifted weights in both hands simultaneously. She demonstrated an unusual split in awareness, being motorically aware of and actively engaged with left-sided weights while being unaware of their incremental changes.     

Artificial consciousness and the consciousness-attention dissociation

Artificial Intelligence is at a turning point, with a substantial increase in projects aiming to implement sophisticated forms of human intelligence in machines. This research attempts to model specific forms of intelligence through brute-force search heuristics and also reproduce features of human perception and cognition, including emotions. Such goals have implications for artificial consciousness, with some arguing that it will be achievable once we overcome short-term engineering challenges. We believe, however, that phenomenal consciousness cannot be implemented in machines. This becomes clear when considering emotions and examining the dissociation between consciousness and attention in humans. While we may be able to program ethical behavior based on rules and machine learning, we will never be able to reproduce emotions or empathy by programming such control systems—these will be merely simulations. Arguments in favor of this claim include considerations about evolution, the neuropsychological aspects of emotions, and the dissociation between attention and consciousness found in humans. Ultimately, we are far from achieving artificial consciousness.     

Perceptual learning effect on decision and confidence thresholds

Practice can enhance of perceptual sensitivity, a well-known phenomenon called perceptual learning. However, the effect of practice on subjective perception has received little attention. We approach this problem from a visual psychophysics and computational modeling perspective. In a sequence of visual search experiments, subjects significantly increased the ability to detect a “trained target”. Before and after training, subjects performed two psychophysical protocols that parametrically vary the visibility of the “trained target”: an attentional blink and a visual masking task. We found that confidence increased after learning only in the attentional blink task. Despite large differences in some observables and task settings, we identify common mechanisms for decision-making and confidence. Specifically, our behavioral results and computational model suggest that perceptual ability is independent of processing time, indicating that changes in early cortical representations are effective, and learning changes decision criteria to convey choice and confidence.     

Is Physical Abuse,Neglect, or a Combination of Both More Predictive of Delinquent Behavior in a High-Risk Population?

This study explored early abuse type and severity in relation to delinquency utilizing an archival longitudinal data set. These data were collected every 2 years, starting at age 4, from the individuals, caregivers, and teachers. Mean differences tests were conducted to determine how delinquency scores varied by abuse type and severity. These analyses used Child Protective Services reports of the type and severity of abuse as independent measures and the behavior problem scale from the Child Behavior Checklist, Youth Self Report, and Teacher Report Form as independent measures. Follow-up analyses of variance and post-hoc tests were conducted as necessary to clarify the relationship between abuse and delinquency. Although results did not reach significance, a relatively small mean difference was discovered between severity types (more severe maltreatment history demonstrating higher levels of delinquency) for teacher ratings of delinquency.     

Disentangling boundary extension and normalization of view memory for scenes

Boundary extension (BE) is a memory error for close-up views of scenes in which participants tend to remember a picture of a scene as depicting a more wide-angle view than what was actually displayed. However, some experiments have yielded data that indicate a normalized memory of the views depicted in a set of scenes, suggesting that memory for the previously studied scenes has become drawn toward the average view in the image set. In previous studies, normalization is only found when the retention interval is very long or when the stimuli no longer appear to represent a spatial expanse. In Experiment 1, we examine whether normalization can influence results for scenes depicting a partial view of space and when the memory test occurs immediately following the study block by manipulating the degree of difference between studied close-up and wide-angle scenes. In Experiment 2, normalization is induced in a set of scenes by creating conditions expected to lead to memory interference, suggesting that this may be the cause of view normalization. Based on the multi-source model of BE, these scenes should be extended during perception (Intraub, H. (2010). Rethinking scene perception: A multisource model. Psychology of Learning and Motivation, 52, 231–265). In Experiment 3, we show that BE is indeed observable if the same scenes are tested differently, supporting the notion that BE is primarily a perceptual phenomenon while normalization is a memory effect.     

Is gaze behaviour in a laboratory context similar to that in real-life? A study in bicyclists

Numerous laboratory-based studies recorded eye movements in participants with varying expertise when watching video projections in the lab. Although research in the lab offers the advantage of internal validity, reliability and ethical considerations, ecological validity is often questionable. Therefore the current study compared visual search in 13 adult cyclists, when cycling a real bicycle path and while watching a film clip of the same road. Dwell time towards five Areas of Interest (AOIs) is analysed. Dwell time (%) in the lab and real-life was comparable only for the low quality bicycle path. Both in real-life and the lab, gaze is predominantly driven towards the road. Since gaze behaviour in the lab and real-life tends to be comparable with increasing task-complexity (road quality), it is concluded that under certain task constraints laboratory experiments making use of video clips might provide valuable information regarding gaze behaviour in real-life.