Right-lateralised lane keeping in young and older British drivers

Young adults demonstrate a small, but consistent, asymmetry of spatial attention favouring the left side of space (“pseudoneglect”) in laboratory-based tests of perception. Conversely, in more naturalistic environments, behavioural errors towards the right side of space are often observed. In the older population, spatial attention asymmetries are generally diminished, or even reversed to favour the right side of space, but much of this evidence has been gained from lab-based and/or psychophysical testing. In this study we assessed whether spatial biases can be elicited during a simulated driving task, and secondly whether these biases also shift with age, in line with standard lab-based measures. Data from 77 right-handed adults with full UK driving licences (i.e. prior experience of left-lane driving) were analysed: 38 young (mean age = 21.53) and 39 older adults (mean age = 70.38). Each participant undertook 3 tests of visuospatial attention: the landmark task, line bisection task, and a simulated lane-keeping task. We found leftward biases in young adults for the landmark and line bisection tasks, indicative of pseudoneglect, and a mean lane position towards the right of centre. In young adults the leftward landmark task biases were negatively correlated with rightward lane-keeping biases, hinting that a common property of the spatial attention networks may have influenced both tasks. As predicted, older adults showed no group-level spatial asymmetry on the landmark nor the line bisection task, but they maintained a mean rightward lane position, similar to young adults. The 3 tasks were not inter-correlated in the older group. These results suggest that spatial biases in older adults may be elicited more effectively in experiments involving complex behaviour rather than abstract, lab-based measures. More broadly, these results confirm that lateral biases of spatial attention are linked to driving behaviour, and this could prove informative in the development of future vehicle safety and driving technology

The Ouroboros Model

At the core of the Ouroboros Model lies a self-referential recursive process with alternating phases of data acquisition and evaluation. Memory entries are organized in schemata. Activation at a time of part of a schema biases the whole structure and, in particular, missing features, thus triggering expectations. An iterative recursive monitor process termed ‘consumption analysis’ is then checking how well such expectations fit with successive activations. A measure for the goodness of fit, “emotion”, provides feedback as (self-) monitoring signal. Contradictions between anticipations based on previous experience and actual current data are highlighted as well as minor gaps and deficits. The basic algorithm can be applied to goal directed movements as well as to abstract rational reasoning when weighing evidence for and against some remote theories. A sketch is provided how the Ouroboros Model can shed light on rather different characteristics of human behavior including learning and meta-learning. Partial implementations proved effective in dedicated safety systems

Change blindness: eradication of gestalt strategies

Arrays of eight, texture-defined rectangles were used as stimuli in a one-shot change blindness (CB) task where there was a 50% chance that one rectangle would change orientation between two successive presentations separated by an interval. CB was eliminated by cueing the target rectangle in the first stimulus, reduced by cueing in the interval and unaffected by cueing in the second presentation. This supports the idea that a representation was formed that persisted through the interval before being 'overwritten' by the second presentation (Landman et al, 2003 Vision Research 43149–164]. Another possibility is that participants used some kind of grouping or Gestalt strategy. To test this we changed the spatial position of the rectangles in the second presentation by shifting them along imaginary spokes (by ±1 degree) emanating from the central fixation point. There was no significant difference seen in performance between this and the standard task [F(1,4)=2.565, p=0.185]. This may suggest two things: (i) Gestalt grouping is not used as a strategy in these tasks, and (ii) it gives further weight to the argument that objects may be stored and retrieved from a pre-attentional store during this task

Keep your eyes on the goal! The impact of consumer goal pursuit on the effectiveness of subtle marketing cues

Consumers are exposed daily to various subtle marketing stimuli such as colors, brand logos, products characterized by multiple attributes or advertising messages bombarding them from numerous channels. All these subtle marketing cues can influence consumer judgment and decision-making, very often without their awareness. This dissertation demonstrates how states of varying motivational intensity (active vs. completed goals; unfulfilled vs. fulfilled desires) affect how consumers respond to such subtle marketing cues. Some examples of such cues specifically explored in this dissertation are primes (subtle cues incidentally activating knowledge structures such as trait concepts and stereotypes; Bargh, Chen, and Burrows 1996) or assortment cues. These subtle marketing stimuli are often embedded in the context, but are at the same time inconspicuous and unobtrusive, mildly steering consumers into specific decisions and choices. Through a specific focus on states of varying motivational intensity this dissertation pinpoints when and how subtle marketing cues are most likely to influence consumer judgment, decision-making, and behavior. As such, it presents a more refined picture looking at processing of contextual information through the lens of currently active motivations. Therefore, the main contribution of this work is to contextualize previous findings, demonstrating not only when subtle contextual cues (e.g, primes, assortment cues) drive consumer decision-making, but also when they fail to shape these decisions

Keep your eyes on the goal! The impact of consumer goal pursuit on the effectiveness of subtle marketing cues

Consumers are exposed daily to various subtle marketing stimuli such as colors, brand logos, products characterized by multiple attributes or advertising messages bombarding them from numerous channels. All these subtle marketing cues can influence consumer judgment and decision-making, very often without their awareness. This dissertation demonstrates how states of varying motivational intensity (active vs. completed goals; unfulfilled vs. fulfilled desires) affect how consumers respond to such subtle marketing cues. Some examples of such cues specifically explored in this dissertation are primes (subtle cues incidentally activating knowledge structures such as trait concepts and stereotypes; Bargh, Chen, and Burrows 1996) or assortment cues. These subtle marketing stimuli are often embedded in the context, but are at the same time inconspicuous and unobtrusive, mildly steering consumers into specific decisions and choices. Through a specific focus on states of varying motivational intensity this dissertation pinpoints when and how subtle marketing cues are most likely to influence consumer judgment, decision-making, and behavior. As such, it presents a more refined picture looking at processing of contextual information through the lens of currently active motivations. Therefore, the main contribution of this work is to contextualize previous findings, demonstrating not only when subtle contextual cues (e.g, primes, assortment cues) drive consumer decision-making, but also when they fail to shape these decisions

Gaze Behaviour during Space Perception and Spatial Decision Making

A series of four experiments investigating gaze behavior and decision making in the context of wayfinding is reported. Participants were presented with screen-shots of choice points taken in large virtual environments. Each screen-shot depicted alternative path options. In Experiment 1, participants had to decide between them in order to find an object hidden in the environment. In Experiment 2, participants were first informed about which path option to take as if following a guided route. Subsequently they were presented with the same images in random order and had to indicate which path option they chose during initial exposure. In Experiment 1, we demonstrate (1) that participants have a tendency to choose the path option that featured the longer line of sight, and (2) a robust gaze bias towards the eventually chosen path option. In Experiment 2, systematic differences in gaze behavior towards the alternative path options between encoding and decoding were observed. Based on data from Experiments 1 & 2 and two control experiments ensuring that fixation patterns were specific to the spatial tasks, we develop a tentative model of gaze behavior during wayfinding decision making suggesting that particular attention was paid to image areas depicting changes in the local geometry of the environments such as corners, openings, and occlusions. Together, the results suggest that gaze during a wayfinding tasks is directed toward, and can be predicted by, a subset of environmental features and that gaze bias effects are a general phenomenon of visual decision making

Neural models of inter-cortical networks in the primate visual system for navigation, attention, path perception, and static and kinetic figure-ground perception

Vision provides the primary means by which many animals distinguish foreground objects from their background and coordinate locomotion through complex environments. The present thesis focuses on mechanisms within the visual system that afford figure-ground segregation and self-motion perception. These processes are modeled as emergent outcomes of dynamical interactions among neural populations in several brain areas. This dissertation specifies and simulates how border-ownership signals emerge in cortex, and how the medial superior temporal area (MSTd) represents path of travel and heading, in the presence of independently moving objects (IMOs). Neurons in visual cortex that signal border-ownership, the perception that a border belongs to a figure and not its background, have been identified but the underlying mechanisms have been unclear. A model is presented that demonstrates that inter-areal interactions across model visual areas V1-V2-V4 afford border-ownership signals similar to those reported in electrophysiology for visual displays containing figures defined by luminance contrast. Competition between model neurons with different receptive field sizes is crucial for reconciling the occlusion of one object by another. The model is extended to determine border-ownership when object borders are kinetically-defined, and to detect the location and size of shapes, despite the curvature of their boundary contours. Navigation in the real world requires humans to travel along curved paths. Many perceptual models have been proposed that focus on heading, which specifies the direction of travel along straight paths, but not on path curvature. In primates, MSTd has been implicated in heading perception. A model of V1, medial temporal area (MT), and MSTd is developed herein that demonstrates how MSTd neurons can simultaneously encode path curvature and heading. Human judgments of heading are accurate in rigid environments, but are biased in the presence of IMOs. The model presented here explains the bias through recurrent connectivity in MSTd and avoids the use of differential motion detectors which, although used in existing models to discount the motion of an IMO relative to its background, is not biologically plausible. Reported modulation of the MSTd population due to attention is explained through competitive dynamics between subpopulations responding to bottom-up and top- down signals

A MULTIMETHOD EXAMINATION OF PSEUDONEGLECT AND AGING

Neurologically healthy adults display a reliable leftward perceptual bias during visuospatial tasks, and this bias appears to change with age. The goal of the current research was to provide an examination of age-related differences in the expression of pseudoneglect and explore whether a shift in the perceptual bias with age was associated with daily activities, such as driving. Chapter 1 provides an overview of hemispatial neglect and pseudoneglect. Chapter 2 reports on results of an Internet-based survey in which the developmental trajectory of pseudoneglect was investigated using the greyscales task, which is known to generate a stronger and more consistent leftward bias among adults than similar tasks. Age was found to be positively correlated with a leftward bias, and the oldest age group exhibited a significantly stronger leftward bias compared to the youngest age group. Chapter 3 outlines the results of a systematic review that was used to synthesize previous literature that has examined the association between age and pseudoneglect. The systematic search revealed that five different tasks have been used to examine pseudoneglect in younger and older adults, and that participants over 60 years of age have demonstrated inconsistent perceptual biases (e.g., enhanced leftward bias, suppressed leftward bias, and rightward bias). The objectives of the quasi-experiment reported in Chapter 4 were to replicate the findings presented in Chapter 2 in a laboratory environment, and further understand influential methodological (e.g., task demands) and individual factors (e.g., normative and non-normative aging) on performance. Again, older adults, whether healthy or displaying symptoms of cognitive impairment, exhibited a leftward bias comparable to younger adults on the greyscales task, but demonstrated a weaker leftward bias on the landmark task. The study presented in Chapter 5 explored the potential association between age-related differences in pseudoneglect and driving by examining location of impact data associated with crashes and near crashes retrieved from a database of real-world driving behaviour. In contrast with results from laboratory environments, age was not associated with location of impact during crashes and near crashes, and overall, crashes were 1.41 times as likely to occur on the left compared to the right side of participants’ vehicles. Chapter 6 summarizes the findings presented in prior chapters and notes potential future directions. Together, the results of both laboratory and naturalistic studies outlines the variability in pseudoneglect demonstrated by healthy older adults, informs future research regarding the importance of task demands and non-normative aging, and highlights the potential implications of lateral perceptual biases