Feature-based attention to unconscious shapes and colors

Hauch

Atten Percept Psychophys

2015

Self Cite

Rapid motor responses to visual stimuli can involve both the activation and inhibition of motor responses. Here, we trace the early processing dynamics of response generation, examining whether activation and inhibition events form a strict sequence when elicited by sequential stimuli, as we would expect if motor events are driven by fast, stimulustriggered feedforward sweeps. We employed identical stimuli in two complementary paradigms. In response priming, responses to a target stimulus are speeded or slowed by a masked prime triggering the same or an alternative response, respectively. By prolonging the prime-target interval, the response-priming effect can reverse to form the negative compatibility effect (NCE), especially when the mask contains response-relevant features. We report two experiments in which primed pointing movements going in ten possible directions were measured with response-relevant, response-irrelevant, or no masks interleaved between the primes and targets, while selective visual attention was varied. We showed that in response priming, initial responses are controlled exclusively by the prime. In the NCE, however, even the earliest movement phase is controlled jointly by the prime, mask, and target information, and a massive force in counterdirection to the primed response reverses the priming effects specifically for slow responses. We conclude that response priming reflects a strict sequence of feedforward response activations, whereas the activation/inhibition events in the NCE are not strictly serial, but integrate information from the different stimuli over time. Even though the mask features and visual attention modulate the NCE, its major source is a mask-induced, direction-specific thrust reversal of the initial response.

Section: Discussionsupporting

confidence: 68%

Section: Resultsmentioning

confidence: 99%

Section: Methodsmentioning

confidence: 99%

Section: Discussionmentioning

confidence: 99%

See 2 more Smart Citations

Mask-triggered thrust reversal in the negative compatibility effect

Hauch

Atten Percept Psychophys

2015

Self Cite

Consciousness and Cognition

“…In particular, recent work by Chica and shown to be deployed to unseen stimuli in a feature-based manner, where visual targets are selected on the basis of a single attribute (e.g. colour or shape), in a manner that is rapid and not dependent on learning (Schmidt & Schmidt, 2010). There is also some evidence from the neurological condition 'blindsight' that stimuli which gain a processing advantage as a consequence of attention guided by visual transients can, nevertheless, remain unseen (Kentridge et al, 1999).…”

Section: General Introductionmentioning

confidence: 99%

Exogenous attention to unseen objects?

Norman

Heywood

2015

The full-text may be used and/or reproduced, and given to third parties in any format or medium, without prior permission or charge, for personal research or study, educational, or not-for-pro t purposes provided that:• a full bibliographic reference is made to the original source • a link is made to the metadata record in DRO • the full-text is not changed in any way The full-text must not be sold in any format or medium without the formal permission of the copyright holders.Please consult the full DRO policy for further details. shown that not all attended stimuli give rise to awareness. Controversy still remains over whether, and the extent to which, a dissociation between attention and awareness encompasses all forms of attention. For example, it has been suggested that attention without awareness is more readily demonstrated for voluntary, endogenous attention than its reflexive, exogenous counterpart. Here we examine whether exogenous attentional cueing can have selective behavioural effects on stimuli that nevertheless remain unseen.Using a task in which object-based attention has been shown in the absence of awareness,we remove all possible contingencies between cues and target stimuli to ensure that any cueing effects must be under purely exogenous control, and find evidence of exogenous object-based attention without awareness. In a second experiment we address whether this dissociation crucially depends on the method used to establish that the objects indeed remain unseen. Specifically, to confirm that objects are unseen we adopt appropriate signal detection task procedures, including those that retain parity with the primary attentional task (by requiring participants to discriminate the two types of trial that are used to measure an effect of attention). We show a significant object-based attention effect is apparent under conditions where the selected object indeed remains undetectable. General IntroductionHistorically, visual attention and visual awareness have often been viewed as being so intimately related that they may be considered aspects of a single underlying process. It is now well established that this is not the case -attention and awareness dissociate under many conditions (McCormick, 1997;Kentridge, Heywood & Weiskrantz, 1999Kentridge, Nijboer & Heywood, 2008;Bahrami, Carmel, Walsh, Rees & Lavie, 2008; Kanai, Tsuchiya & Verstraten, 2006). There is some ambiguity, however, in classic experimental designs manipulating spatial attention (e.g. Posner, 1980) as to whether the unit of attentional selection is a region of space or the object that occupies that space (see e.g.Mole, 2008). One might be perfectly aware of attending to a spatial location even when stimuli appearing at that location remain unseen.This ambiguity is resolved in tests of object-based attention. In this form of attention the 'object' of selection is explicitly provided by the experimenter and it is easy to distinguish between effects that are purely spatial and those involving selection of the cued object. For exa...

ERP signs of categorical and supra-categorical processing of visual information

Zani

Marsili

Senerchia

et al. 2015

Biological Psychology

Overall, the present ERP results revealed shared and distinct mechanisms of access to supra-categorical and categorical knowledge in the same way in which shared and distinct neural representations underlie the processing of diverse semantic categories. Additionally, they outlined the serial nature of categorical and supra-categorical representations, indicating the sequential steps of access to these separate knowledge types.