Medium versus difficult visual search: How a quantitative change in the functional visual field leads to a qualitative difference in performance.

The dominant theories of visual search assume that search is a process involving comparisons of individual items against a target description that is based on the properties of the target in isolation. Here, we present four experiments that demonstrate that this holds true only in difficult search. In medium search it seems that the relation between the target and neighbouring items is also part of the target description.

The role of transients in action observation.

A large number of studies have now described the various ways in which the observation of another person's dynamic movement can influence the speed with which the observer is able to prepare a motor action themselves. The typical results are most often explained with reference to theories that link perception and action. Such theories argue that the cognitive structures associated with each share common representations.

Are goal states represented during kinematic imitation?

A number of studies have shown that observation of another person's actions can modulate one's own actions, such as when 2 individuals cooperate in order to complete a joint task. However, little is known about whether or not direct matching of specific movements is modulated by the goals of the actions observed. In a series of 7 experiments, we employed an action observation paradigm in which 2 coactors sat opposite each other and took turns to reach out to targets presented on a shared workspace.

Response-specific effects in a joint action task: social inhibition of return effects do not emerge when observed and executed actions are different.

Although the inhibition of return (IOR) effect is primarily studied when people act individually, IOR is also observed in social environments where a person observes a partner's response before executing their own response (social or sIOR). Specifically, an observer takes longer to initiate a response to a target at a location that another individual has just responded to than to another location. The present study was conducted to determine if sIOR emerges when two individuals execute different actions-one participant executed keypress responses and the other completed aiming movements to the same set of stimuli.

Action or attention in social inhibition of return?

When two individuals alternate reaching responses to targets located in a visual display, reaction times are longer when responses are directed to where the co-actor just responded. Although an abundance of work has examined the many characteristics of this phenomenon it is not yet known why the effect occurs. In particular, some authors have argued that action representation mechanisms are central to the effect.

Peripheral cues and gaze direction jointly focus attention and inhibition of return.

Centrally presented gaze cues typically elicit a delayed inhibition of return (IOR) effect compared to peripheral exogenous cues. We investigated whether gaze cues elicit early onset IOR when presented peripherally. Faces were presented in the left or right peripheral hemifields, which then gazed upward or downward.

When your decisions are not (quite) your own: action observation influences free choices.

A growing number of studies have begun to assess how the actions of one individual are represented in an observer. Using a variant of an action observation paradigm, four experiments examined whether one person's behaviour can influence the subjective decisions and judgements of another. In Experiment 1, two observers sat adjacent to each other and took turns to freely select and reach to one of two locations.

Is social inhibition of return due to action co-representation?

When two individuals alternate reaching responses to visual targets presented on a shared workspace, one individual is slower to respond to targets occupying the same position as their partner's previous response. This phenomenon is thought to be due to processes that inhibit the initiation of a movement to a location recently acted upon. However, two distinct forms of the inhibition account have been posited, one based on inhibition of an action, the other based on inhibition of an action and location.

Looming motion primes the visuomotor system.

A wealth of evidence now shows that human and animal observers display greater sensitivity to objects that move toward them than to objects that remain static or move away. Increased sensitivity in humans is often evidenced by reaction times that increase in rank order from looming, to receding, to static targets. However, it is not clear whether the processing advantage enjoyed by looming motion is mediated by the attention system or the motor system.

Visual cognition during real social interaction.

Laboratory studies of social visual cognition often simulate the critical aspects of joint attention by having participants interact with a computer-generated avatar. Recently, there has been a movement toward examining these processes during authentic social interaction. In this review, we will focus on attention to faces, attentional misdirection, and a phenomenon we have termed social inhibition of return (Social IOR), that have revealed aspects of social cognition that were hitherto unknown.

Do action goals mediate social inhibition of return?

Social inhibition of return is the phenomenon whereby an individual is slower to reach to locations to which another individual has recently responded. Although this suggests that an observer represents another person's action, little is known about which aspects of the action are encoded. The present work describes a series of three experiments examining whether social inhibition of return represents the endpoint goal of the action, i.

Non-transient luminance changes do not capture attention.

The processing of luminance change is a ubiquitous feature of the human visual system and provides the basis for the rapid orienting of attention to potentially important events (e.g., motion onset, object onset).

Social inhibition of return.

Responses to a target stimulus can be slower when it appears in the same rather than a different location to a previous event, an effect known as inhibition of return (IOR). Recently, it has been shown that when two people alternate responses to a target, one person's responses are slower when they are directed to the same locations as their partner's previous response. The present study sought to investigate this highly novel effect, which we term social IOR (SIOR), in relation to what is known of IOR in individuals performing alone.

Prioritization of looming and receding objects: equal slopes, different intercepts.

Franconeri and Simons (2003) reported that simulated looming objects (marked by a size increase) captured attention, whereas simulated receding objects (marked by a size decrease) did not. This finding has been challenged with the demonstration that receding objects can capture attention when they move in three-dimensional depth. In the present study, we compared the effects of objects that either loomed or receded in depth.

Object and spatial representations in the corner enhancement effect.

Cole, Gellatly, and Blurton have shown that targets presented adjacent to geometric corners are detected more efficiently than targets presented adjacent to straight edges. In six experiments, we examined how this corner enhancement effect is modulated by corner-of-object representations (i.e.

Magnetic stimulation of the left visual cortex impairs expert word recognition.

One of the hallmarks of expert reading is the ability to identify arrays of several letters quickly and in parallel. Such length-independent reading has only been found for word stimuli appearing in the right visual hemifield (RVF). With left hemifield presentation (LVF), response times increase as a function of word length.