David Soto | Universitat Oberta de Catalunya (original) (raw)

Papers by David Soto

European Journal of Neuroscience, 2009

The deployment of visual attention can be strongly modulated by stimuli matching the contents of ... more The deployment of visual attention can be strongly modulated by stimuli matching the contents of working memory (WM), even when WM contents are detrimental to performance and salient bottom-up cues define the critical target [D. Soto et al. (2006)Vision Research, 46, 1010–1018]. Here we investigated the electrophysiological correlates of this early guidance of attention by WM in humans. Observers were presented with a prime to either identify or hold in memory. Subsequently, they had to search for a target line amongst different distractor lines. Each line was embedded within one of four objects and one of the distractor objects could match the stimulus held in WM. Behavioural data showed that performance was more strongly affected by the prime when it was held in memory than when it was merely identified. An electrophysiological measure of the efficiency of target selection (the N2pc) was also affected by the match between the item in WM and the location of the target in the search task. The N2pc was enhanced when the target fell in the same visual field as the re-presented (invalid) prime, compared with when the prime did not reappear in the search display (on neutral trials) and when the prime was contralateral to the target. Merely identifying the prime produced no effect on the N2pc component. The evidence suggests that WM modulates competitive interactions between the items in the visual field to determine the efficiency of target selection.

Proceedings of The National Academy of Sciences, 2006

Trends in Cognitive Sciences, 2008

Recent research has shown interactions between the process of keeping information ‘online’ in wor... more Recent research has shown interactions between the process of keeping information ‘online’ in working memory, and the processes that select relevant information for a response. In particular, our ability to select stimuli in the environment can be modulated by whether the stimuli match the current contents of working memory. Guidance of selection from working memory occurs automatically, even when it is detrimental to performance. Neurophysiological data, from functional brain imaging, indicate that the interaction between working memory and attention is based on neuronal mechanisms distinct from the processes mediating ‘bottom-up’ priming effects from implicit memory. We discuss the importance of ‘top-down’ influences from working memory on the ‘early’ deployment of attention and on the processes that gate visual information into awareness.

Attention Perception & Psychophysics, 2008

Four experiments explored the effect of cognitive load on the time course of top-down guidance of... more Four experiments explored the effect of cognitive load on the time course of top-down guidance of attention from working memory (WM). Observers had to search for a target presented among several distractors, with the target and distractor stimuli embedded inside different objects. On half of the trials, one of the distractor objects was cued by a matching item held in WM. When a single item was maintained in memory, search performance was impaired relative to a neutral baseline, where the memory and search displays did not match. These effects of WM on subsequent search were reduced by including a verbal suppression task during the WM and search displays, and by varying the WM load. The degree of competition for resources in WM is a key factor in determining the time course and magnitude of the interaction between WM and visual selection.

Journal of Experimental Psychology-learning Memory and Cognition, 2010

We show that perceptual sensitivity to visual stimuli can be modulated by matches between the con... more We show that perceptual sensitivity to visual stimuli can be modulated by matches between the contents of working memory (WM) and stimuli in the visual field. Observers were presented with an object cue (to hold in WM or to merely attend) and subsequently had to identify a brief target presented within a colored shape. The cue could be re-presented in the display, where it surrounded either the target (on valid trials) or a distractor (on invalid trials). Perceptual identification of the target, as indexed by A', was enhanced on valid relative to invalid trials but only when the cue was kept in WM. There was minimal effect of the cue when it was merely attended and not kept in WM. Verbal cues were as effective as visual cues at modulating perceptual identification, and the effects were independent of the effects of target saliency. Matches to the contents of WM influenced perceptual sensitivity even under conditions that minimized competition for selecting the target. WM cues were also effective when targets were less likely to fall in a repeated WM stimulus than in other stimuli in the search display. There were no effects of WM on decisional criteria, in contrast to sensitivity. The findings suggest that reentrant feedback from WM can affect early stages of perceptual processing.

Journal of Experimental Psychology-human Perception and Performance, 2007

Previous studies have shown that visual attention can be captured by stimuli matching the content... more Previous studies have shown that visual attention can be captured by stimuli matching the contents of working memory (WM). Here, the authors assessed the nature of the representation that mediates the guidance of visual attention from WM. Observers were presented with either verbal or visual primes (to hold in memory, Experiment 1; to verbalize, Experiment 2; or merely to attend, Experiment 3) and subsequently were required to search for a target among different distractors, each embedded within a colored shape. In half of the trials, an object in the search array matched the prime, but this object never contained the target. Despite this, search was impaired relative to a neutral baseline in which the prime and search displays did not match. An interesting finding is that verbal primes were effective in generating the effects, and verbalization of visual primes elicited similar effects to those elicited when primes were held in WM. However, the effects were absent when primes were only attended. The data suggest that there is automatic encoding into WM when items are verbalized and that verbal as well as visual WM can guide visual attention.

Experimental Psychology, 2009

Recent research has shown that the contents of working memory (WM) can guide the early deployment... more Recent research has shown that the contents of working memory (WM) can guide the early deployment of attention in visual search. Here, we assessed whether this guidance occurred for all attributes of items held in WM, or whether effects are based on just the attributes relevant for the memory task. We asked observers to hold in memory just the shape of a coloured object and to subsequently search for a target line amongst distractor lines, each embedded within a different object. On some trials, one of the objects in the search display could match the shape, the colour or both dimensions of the cue, but this object never contained the relevant target line. Relative to a neutral baseline, where there was no match between the memory and the search displays, search performance was impaired when a distractor object matched both the colour and the shape of the memory cue. The implications for the understanding of the interaction between WM and selection are discussed.

Neuropsychologia, 2006

Working memory plays a crucial role in the control of visual selection. Previous research has sho... more Working memory plays a crucial role in the control of visual selection. Previous research has shown that attentional deployment can be biased to objects in an array matching the contents of working memory. Here, we examined the role of the frontal cortex in determining the interaction between working memory and attention. At the start of each trial, participants memorized an object cue that could contain either the target or a distracter, when the object reappeared in the subsequent search array. Relative to age-matched controls, patients suffering from damage to the frontal lobes showed a stronger effect of the memory stimulus on search. Interestingly, there was an effect of frontal damage on the mean latencies to fixate targets but the effect of memory validity on the number of first saccades to the target, and their time of initiation, was similar across the groups. The results suggest that, following the earliest deployment of attention, frontal lobe structures are involved in separating relevant target from irrelevant (object cue) information, when both are held in memory.

Proceedings of The National Academy of Sciences, 2009

Proceedings of The National Academy of Sciences, 2007

Journal of Experimental Psychology-human Perception and Performance, 2005

Acta Psychologica, 2002

In this paper, we study the effects of spatial attention on detection and identification of orien... more In this paper, we study the effects of spatial attention on detection and identification of oriented lines presented at near-threshold luminance. In the first experiment, we found that the cuing effect was greater when observers had to discriminate between two close orientations than when they had to discriminate between two far-apart orientations. In the second experiment, we examined the effects of peripheral cues on summation of low-contrast oriented lines. We found that the range of orientations within which summation occurred was greater when the cues were invalid than when they were valid. Our results suggest that attention to a specific location in the visual field modulates the neural channels which code orientation in at least two different ways: (a) spatial attention increases the responsivity of these channels to stimuli presented at this location, and (b) it reduces the bandwidths or ranges of orientations to which these channels are sensitive. These results suggest that the properties of the orientation-tuned channels, including those that seem to exert their effects at early stages of orientation processing (e.g., tuning function), may not be fixed, but rather vary according to the attention being paid to the spatial region within which the target stimulus is presented.

European Journal of Neuroscience, 2009

The deployment of visual attention can be strongly modulated by stimuli matching the contents of ... more The deployment of visual attention can be strongly modulated by stimuli matching the contents of working memory (WM), even when WM contents are detrimental to performance and salient bottom-up cues define the critical target [D. Soto et al. (2006)Vision Research, 46, 1010–1018]. Here we investigated the electrophysiological correlates of this early guidance of attention by WM in humans. Observers were presented with a prime to either identify or hold in memory. Subsequently, they had to search for a target line amongst different distractor lines. Each line was embedded within one of four objects and one of the distractor objects could match the stimulus held in WM. Behavioural data showed that performance was more strongly affected by the prime when it was held in memory than when it was merely identified. An electrophysiological measure of the efficiency of target selection (the N2pc) was also affected by the match between the item in WM and the location of the target in the search task. The N2pc was enhanced when the target fell in the same visual field as the re-presented (invalid) prime, compared with when the prime did not reappear in the search display (on neutral trials) and when the prime was contralateral to the target. Merely identifying the prime produced no effect on the N2pc component. The evidence suggests that WM modulates competitive interactions between the items in the visual field to determine the efficiency of target selection.

Proceedings of The National Academy of Sciences, 2006

Trends in Cognitive Sciences, 2008

Recent research has shown interactions between the process of keeping information ‘online’ in wor... more Recent research has shown interactions between the process of keeping information ‘online’ in working memory, and the processes that select relevant information for a response. In particular, our ability to select stimuli in the environment can be modulated by whether the stimuli match the current contents of working memory. Guidance of selection from working memory occurs automatically, even when it is detrimental to performance. Neurophysiological data, from functional brain imaging, indicate that the interaction between working memory and attention is based on neuronal mechanisms distinct from the processes mediating ‘bottom-up’ priming effects from implicit memory. We discuss the importance of ‘top-down’ influences from working memory on the ‘early’ deployment of attention and on the processes that gate visual information into awareness.

Attention Perception & Psychophysics, 2008

Four experiments explored the effect of cognitive load on the time course of top-down guidance of... more Four experiments explored the effect of cognitive load on the time course of top-down guidance of attention from working memory (WM). Observers had to search for a target presented among several distractors, with the target and distractor stimuli embedded inside different objects. On half of the trials, one of the distractor objects was cued by a matching item held in WM. When a single item was maintained in memory, search performance was impaired relative to a neutral baseline, where the memory and search displays did not match. These effects of WM on subsequent search were reduced by including a verbal suppression task during the WM and search displays, and by varying the WM load. The degree of competition for resources in WM is a key factor in determining the time course and magnitude of the interaction between WM and visual selection.

Journal of Experimental Psychology-learning Memory and Cognition, 2010

We show that perceptual sensitivity to visual stimuli can be modulated by matches between the con... more We show that perceptual sensitivity to visual stimuli can be modulated by matches between the contents of working memory (WM) and stimuli in the visual field. Observers were presented with an object cue (to hold in WM or to merely attend) and subsequently had to identify a brief target presented within a colored shape. The cue could be re-presented in the display, where it surrounded either the target (on valid trials) or a distractor (on invalid trials). Perceptual identification of the target, as indexed by A', was enhanced on valid relative to invalid trials but only when the cue was kept in WM. There was minimal effect of the cue when it was merely attended and not kept in WM. Verbal cues were as effective as visual cues at modulating perceptual identification, and the effects were independent of the effects of target saliency. Matches to the contents of WM influenced perceptual sensitivity even under conditions that minimized competition for selecting the target. WM cues were also effective when targets were less likely to fall in a repeated WM stimulus than in other stimuli in the search display. There were no effects of WM on decisional criteria, in contrast to sensitivity. The findings suggest that reentrant feedback from WM can affect early stages of perceptual processing.

Journal of Experimental Psychology-human Perception and Performance, 2007

Previous studies have shown that visual attention can be captured by stimuli matching the content... more Previous studies have shown that visual attention can be captured by stimuli matching the contents of working memory (WM). Here, the authors assessed the nature of the representation that mediates the guidance of visual attention from WM. Observers were presented with either verbal or visual primes (to hold in memory, Experiment 1; to verbalize, Experiment 2; or merely to attend, Experiment 3) and subsequently were required to search for a target among different distractors, each embedded within a colored shape. In half of the trials, an object in the search array matched the prime, but this object never contained the target. Despite this, search was impaired relative to a neutral baseline in which the prime and search displays did not match. An interesting finding is that verbal primes were effective in generating the effects, and verbalization of visual primes elicited similar effects to those elicited when primes were held in WM. However, the effects were absent when primes were only attended. The data suggest that there is automatic encoding into WM when items are verbalized and that verbal as well as visual WM can guide visual attention.

Experimental Psychology, 2009

Recent research has shown that the contents of working memory (WM) can guide the early deployment... more Recent research has shown that the contents of working memory (WM) can guide the early deployment of attention in visual search. Here, we assessed whether this guidance occurred for all attributes of items held in WM, or whether effects are based on just the attributes relevant for the memory task. We asked observers to hold in memory just the shape of a coloured object and to subsequently search for a target line amongst distractor lines, each embedded within a different object. On some trials, one of the objects in the search display could match the shape, the colour or both dimensions of the cue, but this object never contained the relevant target line. Relative to a neutral baseline, where there was no match between the memory and the search displays, search performance was impaired when a distractor object matched both the colour and the shape of the memory cue. The implications for the understanding of the interaction between WM and selection are discussed.

Neuropsychologia, 2006

Working memory plays a crucial role in the control of visual selection. Previous research has sho... more Working memory plays a crucial role in the control of visual selection. Previous research has shown that attentional deployment can be biased to objects in an array matching the contents of working memory. Here, we examined the role of the frontal cortex in determining the interaction between working memory and attention. At the start of each trial, participants memorized an object cue that could contain either the target or a distracter, when the object reappeared in the subsequent search array. Relative to age-matched controls, patients suffering from damage to the frontal lobes showed a stronger effect of the memory stimulus on search. Interestingly, there was an effect of frontal damage on the mean latencies to fixate targets but the effect of memory validity on the number of first saccades to the target, and their time of initiation, was similar across the groups. The results suggest that, following the earliest deployment of attention, frontal lobe structures are involved in separating relevant target from irrelevant (object cue) information, when both are held in memory.

Proceedings of The National Academy of Sciences, 2009

Proceedings of The National Academy of Sciences, 2007

Journal of Experimental Psychology-human Perception and Performance, 2005

Acta Psychologica, 2002

In this paper, we study the effects of spatial attention on detection and identification of orien... more In this paper, we study the effects of spatial attention on detection and identification of oriented lines presented at near-threshold luminance. In the first experiment, we found that the cuing effect was greater when observers had to discriminate between two close orientations than when they had to discriminate between two far-apart orientations. In the second experiment, we examined the effects of peripheral cues on summation of low-contrast oriented lines. We found that the range of orientations within which summation occurred was greater when the cues were invalid than when they were valid. Our results suggest that attention to a specific location in the visual field modulates the neural channels which code orientation in at least two different ways: (a) spatial attention increases the responsivity of these channels to stimuli presented at this location, and (b) it reduces the bandwidths or ranges of orientations to which these channels are sensitive. These results suggest that the properties of the orientation-tuned channels, including those that seem to exert their effects at early stages of orientation processing (e.g., tuning function), may not be fixed, but rather vary according to the attention being paid to the spatial region within which the target stimulus is presented.