Eye contact facilitates awareness of faces during interocular suppression

Eye contact captures attention and receives prioritized visual processing. Here we asked whether eye contact might be processed outside conscious awareness. Faces with direct and averted gaze were rendered invisible using interocular suppression. In two experiments we found that faces with direct gaze overcame such suppression more rapidly than faces with averted gaze. Control experiments ruled out the influence of low-level stimulus differences and differential response criteria. These results indicate an enhanced unconscious representation of direct gaze, enabling the automatic and rapid detection of other individuals making eye contact with the observer

A basis for the exploration of hypermedia systems : a guided path facility : a thesis presented in partial fulfillment of the requirements for the degree of Master of Arts at Massey University

This thesis examines the potential of a paths facility as an aid to navigating large hypermedia systems. The use of the navigational metaphor as applied to finding information is continued with the idea of following a path through information 'space'. This idea assumes that each node, or chunk of information, on the path can be considered a landmark that can be easily returned to when side-trips are taken off the path to explore the surrounding space. The idea of a guided path assumes the re-use of a path, and also assumes that there is extra information available about the path. This meta-information is very important for providing information to help path-followers make better sense of the path, both in terms of content and context, but also in making more effective use of the nodes on the path and in navigating the variety of interface conventions seen in the test environment - HyperCard. A small pilot study has been carried out using two groups of users performing a directed information-seeking task. One group used HyperCard's navigational facilities to find information in a group of stacks, while the other group used a guided path as a base on which to explore the same group of stacks. Both groups had a time limit, at the end of which they completed a number of questionnaires to indicate task completion, as well as providing a subjective evaluation of the facilities they used. The guided path facility appears to be most effective for inexperienced users for a number of reasons. It presents a simplified view of the complex system - the information available has already been filtered and selected, and a simple and consistent navigational interface reduces the cognitive overheads associated with learning a variety of mechanisms present in different stacks. An important feature of a path facility seems to be the provision of meta-information, especially scope information which can reduce the incidences of disorientation. Another feature is the provision of a history facility which provides a backtracking capability. It may also be used in the creation of paths using the length of visit as a criterion for node inclusion on a new path

Mediating between AI and highly specialized users

We report part of the design experience gained in X-Media, a system for knowledge management and sharing. Consolidated techniques of interaction design (scenario-based design) had to be revisited to capture the richness and complexity of intelligent interactive systems. We show that the design of intelligent systems requires methodologies (faceted scenarios) that support the investigation of intelligent features and usability factors simultaneously. Interaction designers become mediators between intelligent technology and users, and have to facilitate reciprocal understanding

Memory and cognition in schizophrenia.

Episodic memory deficits are consistently documented as a core aspect of cognitive dysfunction in schizophrenia patients, present from the onset of the illness and strongly associated with functional disability. Over the past decade, research using approaches from experimental cognitive neuroscience revealed disproportionate episodic memory impairments in schizophrenia (Sz) under high cognitive demand relational encoding conditions and relatively unimpaired performance under item-specific encoding conditions. These specific deficits in component processes of episodic memory reflect impaired activation and connectivity within specific elements of frontal-medial temporal lobe circuits, with a central role for the dorsolateral prefrontal cortex (DLPFC), relatively intact function of ventrolateral prefrontal cortex and variable results in the hippocampus. We propose that memory deficits can be understood within the broader context of cognitive deficits in Sz, where impaired DLPFC-related cognitive control has a broad impact across multiple cognitive domains. The therapeutic implications of these findings are discussed

S-cone signals invisible to the motion system can improve motion extraction via grouping by color

Peer reviewedPublisher PD

Inside the brain of an elite athlete: The neural processes that support high achievement in sports

Events like the World Championships in athletics and the Olympic Games raise the public profile of competitive sports. They may also leave us wondering what sets the competitors in these events apart from those of us who simply watch. Here we attempt to link neural and cognitive processes that have been found to be important for elite performance with computational and physiological theories inspired by much simpler laboratory tasks. In this way we hope to inspire neuroscientists to consider how their basic research might help to explain sporting skill at the highest levels of performance

The iso-response method

Throughout the nervous system, neurons integrate high-dimensional input streams and transform them into an output of their own. This integration of incoming signals involves filtering processes and complex non-linear operations. The shapes of these filters and non-linearities determine the computational features of single neurons and their functional roles within larger networks. A detailed characterization of signal integration is thus a central ingredient to understanding information processing in neural circuits. Conventional methods for measuring single-neuron response properties, such as reverse correlation, however, are often limited by the implicit assumption that stimulus integration occurs in a linear fashion. Here, we review a conceptual and experimental alternative that is based on exploring the space of those sensory stimuli that result in the same neural output. As demonstrated by recent results in the auditory and visual system, such iso-response stimuli can be used to identify the non-linearities relevant for stimulus integration, disentangle consecutive neural processing steps, and determine their characteristics with unprecedented precision. Automated closed-loop experiments are crucial for this advance, allowing rapid search strategies for identifying iso-response stimuli during experiments. Prime targets for the method are feed-forward neural signaling chains in sensory systems, but the method has also been successfully applied to feedback systems. Depending on the specific question, “iso-response” may refer to a predefined firing rate, single-spike probability, first-spike latency, or other output measures. Examples from different studies show that substantial progress in understanding neural dynamics and coding can be achieved once rapid online data analysis and stimulus generation, adaptive sampling, and computational modeling are tightly integrated into experiments