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Further evidence against a momentum explanation for IOR.

Harris JW, Cowper-Smith CD, Klein RM, Westwood DA - PLoS ONE (2015)

Bottom Line: This observation can be explained as a result of inhibition at the attended location (IOR), or as facilitation at the location opposite the cue (opposite facilitation effect or OFE).Past research has demonstrated that IOR is observed reliably, whereas OFE is observed only occasionally.The present series of four experiments allows us to determine whether or not OFE can be explained by eye movements as suggested by previous authors.

View Article: PubMed Central - PubMed

Affiliation: Division of Kinesiology, School of Health and Human Performance, Faculty of Health Professions, Dalhousie University, Halifax, NS, Canada.

ABSTRACT
Reaction times to targets presented in the same location as a preceding cue are greater than those to targets presented opposite the cued location. This observation can be explained as a result of inhibition at the attended location (IOR), or as facilitation at the location opposite the cue (opposite facilitation effect or OFE). Past research has demonstrated that IOR is observed reliably, whereas OFE is observed only occasionally. The present series of four experiments allows us to determine whether or not OFE can be explained by eye movements as suggested by previous authors. Participants' eye movements were monitored as they were presented with an array of four placeholders aligned with the four cardinal axes. Exogenous cues and targets were presented successively. Participants (N=37) completed either: i.) cue-manual and cue-saccade experiments, ignoring the cue and then responding with a keypress or saccade, respectively, or ii.) manual-manual and saccade-saccade experiments, responding to both the cue and the target with a keypress or saccade respectively. Results demonstrated a reliable IOR effect in each of the four experiments (reaction time greater for same versus adjacent and opposite cue-target trials). None of the four experiments demonstrated evidence of an OFE (reaction times were not significantly lower for opposite versus adjacent cue-target trials). These results are inconsistent with a momentum-based account of cue-target task performance, and furthermore suggest that the OFE cannot be attributed to occasional eye movements to the cue and/or target in previous studies.

No MeSH data available.


Related in: MedlinePlus

Experimental predictions.Representation of the experimental setup (a) and the predictions that are made for reaction time if IOR (b) or attentional momentum (c) are operating. a) Each trial begins with the participant fixating a stimulus at the center of the screen (marked as F). A cue is presented at any of the locations marked by the letters O (orthogonal), U (uncued) and C (cued). In this example the cue is presented to the right of fixation. At the time of the presentation of the target (at any of the 4 peripheral locations where cues could have been presented) it is assumed that attention, after having been captured by the cue has returned to fixation. b, c) Illustrated here are the hypothesized distributions of the effect of IOR (b) and attentional momentum (c) at the time of target presentation. In (b) the circular region, darker than the grey background, represents the inhibited region where RT to targets will be increased. Here a gradient centered on the cued location is assumed. In (c) the wedge-shaped region lighter than the grey background represents the facilitated region where RT to targets will be decreased. Here it is a direction (away from the originally cued direction) that is facilitated with a gradient of decreasing facilitation as the angular deviation of the target's direction from the direction of attentional momentum increases. d) Pattern of results predicted by the gradient of IOR illustrated in panel (b). e) Pattern of results (this will be referred to as the opposite facilitation effect, OFE) predicted by the gradient of attentional momentum illustrated in panel (c).
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pone.0123666.g001: Experimental predictions.Representation of the experimental setup (a) and the predictions that are made for reaction time if IOR (b) or attentional momentum (c) are operating. a) Each trial begins with the participant fixating a stimulus at the center of the screen (marked as F). A cue is presented at any of the locations marked by the letters O (orthogonal), U (uncued) and C (cued). In this example the cue is presented to the right of fixation. At the time of the presentation of the target (at any of the 4 peripheral locations where cues could have been presented) it is assumed that attention, after having been captured by the cue has returned to fixation. b, c) Illustrated here are the hypothesized distributions of the effect of IOR (b) and attentional momentum (c) at the time of target presentation. In (b) the circular region, darker than the grey background, represents the inhibited region where RT to targets will be increased. Here a gradient centered on the cued location is assumed. In (c) the wedge-shaped region lighter than the grey background represents the facilitated region where RT to targets will be decreased. Here it is a direction (away from the originally cued direction) that is facilitated with a gradient of decreasing facilitation as the angular deviation of the target's direction from the direction of attentional momentum increases. d) Pattern of results predicted by the gradient of IOR illustrated in panel (b). e) Pattern of results (this will be referred to as the opposite facilitation effect, OFE) predicted by the gradient of attentional momentum illustrated in panel (c).

Mentions: Posner and Cohen [1] expanded their experimental design to include four possible peripheral cue/target locations (left, right, up and down from centre) to permit a direct comparison between momentum and inhibition accounts, which make different predictions about response times for uncued target locations that are the same distance from fixation and equidistant from the cued location and location opposite the cued location (see Fig 1). We will refer to these uncued locations as "orthogonal". According to the inhibitory tagging account, RTs to uncued-orthogonal locations should be similar to those at the uncued-opposite location (Fig 1b and 1d), as the inhibitory tag is restricted to a gradient around the cued location. According to the opposite facilitation account, targets appearing at locations in the direction of the vector of attentional momentum should show a benefit relative to both the cued and uncued-orthogonal locations (Fig 1c and 1e). An intermediate pattern might be observed if both mechanisms were operating. Posner and Cohen’s [1] results (as described on p. 538 of their paper, conforms to the pattern displayed in Fig 1d favored the inhibitory tagging mechanism over the attentional momentum mechanism, as reaction times for targets appearing at the cued location were slower than to all uncued locations which did not differ from each other.


Further evidence against a momentum explanation for IOR.

Harris JW, Cowper-Smith CD, Klein RM, Westwood DA - PLoS ONE (2015)

Experimental predictions.Representation of the experimental setup (a) and the predictions that are made for reaction time if IOR (b) or attentional momentum (c) are operating. a) Each trial begins with the participant fixating a stimulus at the center of the screen (marked as F). A cue is presented at any of the locations marked by the letters O (orthogonal), U (uncued) and C (cued). In this example the cue is presented to the right of fixation. At the time of the presentation of the target (at any of the 4 peripheral locations where cues could have been presented) it is assumed that attention, after having been captured by the cue has returned to fixation. b, c) Illustrated here are the hypothesized distributions of the effect of IOR (b) and attentional momentum (c) at the time of target presentation. In (b) the circular region, darker than the grey background, represents the inhibited region where RT to targets will be increased. Here a gradient centered on the cued location is assumed. In (c) the wedge-shaped region lighter than the grey background represents the facilitated region where RT to targets will be decreased. Here it is a direction (away from the originally cued direction) that is facilitated with a gradient of decreasing facilitation as the angular deviation of the target's direction from the direction of attentional momentum increases. d) Pattern of results predicted by the gradient of IOR illustrated in panel (b). e) Pattern of results (this will be referred to as the opposite facilitation effect, OFE) predicted by the gradient of attentional momentum illustrated in panel (c).
© Copyright Policy
Related In: Results  -  Collection

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getmorefigures.php?uid=PMC4400106&req=5

pone.0123666.g001: Experimental predictions.Representation of the experimental setup (a) and the predictions that are made for reaction time if IOR (b) or attentional momentum (c) are operating. a) Each trial begins with the participant fixating a stimulus at the center of the screen (marked as F). A cue is presented at any of the locations marked by the letters O (orthogonal), U (uncued) and C (cued). In this example the cue is presented to the right of fixation. At the time of the presentation of the target (at any of the 4 peripheral locations where cues could have been presented) it is assumed that attention, after having been captured by the cue has returned to fixation. b, c) Illustrated here are the hypothesized distributions of the effect of IOR (b) and attentional momentum (c) at the time of target presentation. In (b) the circular region, darker than the grey background, represents the inhibited region where RT to targets will be increased. Here a gradient centered on the cued location is assumed. In (c) the wedge-shaped region lighter than the grey background represents the facilitated region where RT to targets will be decreased. Here it is a direction (away from the originally cued direction) that is facilitated with a gradient of decreasing facilitation as the angular deviation of the target's direction from the direction of attentional momentum increases. d) Pattern of results predicted by the gradient of IOR illustrated in panel (b). e) Pattern of results (this will be referred to as the opposite facilitation effect, OFE) predicted by the gradient of attentional momentum illustrated in panel (c).
Mentions: Posner and Cohen [1] expanded their experimental design to include four possible peripheral cue/target locations (left, right, up and down from centre) to permit a direct comparison between momentum and inhibition accounts, which make different predictions about response times for uncued target locations that are the same distance from fixation and equidistant from the cued location and location opposite the cued location (see Fig 1). We will refer to these uncued locations as "orthogonal". According to the inhibitory tagging account, RTs to uncued-orthogonal locations should be similar to those at the uncued-opposite location (Fig 1b and 1d), as the inhibitory tag is restricted to a gradient around the cued location. According to the opposite facilitation account, targets appearing at locations in the direction of the vector of attentional momentum should show a benefit relative to both the cued and uncued-orthogonal locations (Fig 1c and 1e). An intermediate pattern might be observed if both mechanisms were operating. Posner and Cohen’s [1] results (as described on p. 538 of their paper, conforms to the pattern displayed in Fig 1d favored the inhibitory tagging mechanism over the attentional momentum mechanism, as reaction times for targets appearing at the cued location were slower than to all uncued locations which did not differ from each other.

Bottom Line: This observation can be explained as a result of inhibition at the attended location (IOR), or as facilitation at the location opposite the cue (opposite facilitation effect or OFE).Past research has demonstrated that IOR is observed reliably, whereas OFE is observed only occasionally.The present series of four experiments allows us to determine whether or not OFE can be explained by eye movements as suggested by previous authors.

View Article: PubMed Central - PubMed

Affiliation: Division of Kinesiology, School of Health and Human Performance, Faculty of Health Professions, Dalhousie University, Halifax, NS, Canada.

ABSTRACT
Reaction times to targets presented in the same location as a preceding cue are greater than those to targets presented opposite the cued location. This observation can be explained as a result of inhibition at the attended location (IOR), or as facilitation at the location opposite the cue (opposite facilitation effect or OFE). Past research has demonstrated that IOR is observed reliably, whereas OFE is observed only occasionally. The present series of four experiments allows us to determine whether or not OFE can be explained by eye movements as suggested by previous authors. Participants' eye movements were monitored as they were presented with an array of four placeholders aligned with the four cardinal axes. Exogenous cues and targets were presented successively. Participants (N=37) completed either: i.) cue-manual and cue-saccade experiments, ignoring the cue and then responding with a keypress or saccade, respectively, or ii.) manual-manual and saccade-saccade experiments, responding to both the cue and the target with a keypress or saccade respectively. Results demonstrated a reliable IOR effect in each of the four experiments (reaction time greater for same versus adjacent and opposite cue-target trials). None of the four experiments demonstrated evidence of an OFE (reaction times were not significantly lower for opposite versus adjacent cue-target trials). These results are inconsistent with a momentum-based account of cue-target task performance, and furthermore suggest that the OFE cannot be attributed to occasional eye movements to the cue and/or target in previous studies.

No MeSH data available.


Related in: MedlinePlus