Saccade target selection in visual search: Accuracy improves when more distractors are present

To gain insight into how vision guides eye movements, monkeys were trained to make a single saccade to a specified target stimulus during feature and conjunction search with stimuli discriminated by color and shape. Monkeys performed both tasks at levels well above chance. The latencies of saccades to the target in conjunction search exhibited shallow positive slopes as a function of set size, comparable to slopes of reaction time of humans during target present/absent judgments, but significantly different than the slopes in feature search. Properties of the selection process were revealed by the occasional saccades to distractors. During feature search, errant saccades were directed more often to a distractor near the target than to a distractor at any other location. In contrast, during conjunction search, saccades to distractors were guided more by similarity than proximity to the target; monkeys were significantly more likely to shift gaze to a distractor that had one of the target features than to a distractor that had none. Overall, color and shape information were used to similar degrees in the search for the conjunction target. However, in single sessions we observed an increased tendency of saccades to a distractor that had been the target in the previous experimental session. The establishment of this tendency across sessions at least a day apart and its persistence throughout a session distinguish this phenomenon from the short-term (<10 trials) perceptual priming observed in this and earlier studies using feature visual search. Our findings support the hypothesis that the target in at least some conjunction visual searches can be detected efficiently based on visual similarity, most likely through parallel processing of the individual features that define the stimuli. These observations guide the interpretation of neurophysiological data and constrain the development of computational models.

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Close interactions between “When” and “Where” in saccade target selection: Multiple saliency and distractor effects

Behavioral and Brain Sciences ◽

10.1017/s0140525x99422150 ◽

1999 ◽

Vol 22 (4) ◽

pp. 693-694

Author(s):

Christian Olivers ◽

Dietmar Heinke ◽

Glyn Humphreys ◽

Hermann Müller

Keyword(s):

Visual Search ◽

Target Selection ◽

Saccade Target ◽

Spatial Selection ◽

Distractor Effect ◽

Selection Processes ◽

Remote Distractor Effect ◽

Saccade Generation

A model of when and where saccades are made necessarily incorporates a model of the “When” and “Where” of target selection. We suggest that the framework proposed by Findlay & Walker does not specify sufficiently how (and by what means) selection processes contribute to the spatial and temporal determinants of saccade generation. Examples from across-trial priming in visual search and from the inhibition of temporally segmented distractors show linkage between the processes involved in computing when and where selection operates, so that there is cooperation rather than competition between so-called Where and When pathways. Aspects of spatial selection may also determine the remote distractor effect on saccades. The detailed relations between the processes involved in selection and saccade generation may be best understood in relation to detailed computational accounts of the processes.

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Saccade target selection in visual search: the effect of information from the previous fixation

Vision Research ◽

10.1016/s0042-6989(00)00236-4 ◽

2001 ◽

Vol 41 (1) ◽

pp. 87-95 ◽

Cited By ~ 72

Author(s):

John M Findlay ◽

Valerie Brown ◽

Iain D Gilchrist

Keyword(s):

Visual Search ◽

Target Selection ◽

Saccade Target

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Frontal Eye Field Activity Before Visual Search Errors Reveals the Integration of Bottom-Up and Top-Down Salience

Journal of Neurophysiology ◽

10.1152/jn.00330.2004 ◽

2005 ◽

Vol 93 (1) ◽

pp. 337-351 ◽

Cited By ~ 84

Author(s):

Kirk G. Thompson ◽

Narcisse P. Bichot ◽

Takashi R. Sato

Keyword(s):

Visual Search ◽

Search Task ◽

Target Selection ◽

Saccade Target ◽

Frontal Eye Field ◽

Top Down ◽

Bottom Up ◽

Stimulus Response ◽

Singleton Search ◽

Eye Field

We investigated the saccade decision process by examining activity recorded in the frontal eye field (FEF) of monkeys performing 2 separate visual search experiments in which there were errors in saccade target choice. In the first experiment, the difficulty of a singleton search task was manipulated by varying the similarity between the target and distractors; errors were made more often when the distractors were similar to the target. On catch trials in which the target was absent the monkeys occasionally made false alarm errors by shifting gaze to one of the distractors. The second experiment was a popout color visual search task in which the target and distractor colors switched unpredictably across trials. Errors occurred most frequently on the first trial after the switch and less often on subsequent trials. In both experiments, FEF neurons selected the saccade goal on error trials, not the singleton target of the search array. Although saccades were made to the same stimulus locations, presaccadic activation and the magnitude of selection differed across trial conditions. The variation in presaccadic selective activity was accounted for by the variation in saccade probability across the stimulus–response conditions, but not by variations in saccade metrics. These results suggest that FEF serves as a saccade probability map derived from the combination of bottom-up and top-down influences. Peaks on this map represent the behavioral relevance of each item in the visual field rather than just reflecting saccade preparation. This map in FEF may correspond to the theoretical salience map of many models of attention and saccade target selection.

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Saccade Target Selection During Visual Search

Vision Research ◽

10.1016/s0042-6989(96)00218-0 ◽

1997 ◽

Vol 37 (5) ◽

pp. 617-631 ◽

Cited By ~ 197

Author(s):

JOHN M. FINDLAY

Keyword(s):

Visual Search ◽

Target Selection ◽

Saccade Target

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Neural basis of saccade target selection in frontal eye field during visual search

Nature ◽

10.1038/366467a0 ◽

1993 ◽

Vol 366 (6454) ◽

pp. 467-469 ◽

Cited By ~ 244

Author(s):

Jeffrey D. Schall ◽

Doug P. Hanes

Keyword(s):

Visual Search ◽

Target Selection ◽

Saccade Target ◽

Frontal Eye Field ◽

Neural Basis ◽

Eye Field

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Sequential Operations Revealed by Serendipitous Feature Selectivity in Frontal Eye Field

10.1101/683144 ◽

2019 ◽

Cited By ~ 2

Author(s):

Kaleb A. Lowe ◽

Jeffrey D. Schall

Keyword(s):

Visual Search ◽

Search Task ◽

Visual Search Task ◽

Target Selection ◽

Stimulus Orientation ◽

Saccade Target ◽

Frontal Eye Field ◽

Eye Field ◽

Feature Selectivity ◽

Selection Indexes

ABSTRACTNeurons in macaque frontal eye field contribute to spatial but typically not feature selection during visual search. Using an innovative visual search task, we report a serendipitous discovery that some frontal eye field neurons can develop rapid selectivity for stimulus orientation that is used to guide gaze during a visual search task with pro-saccade and anti-saccade responses. This feature selectivity occurs simultaneously at multiple locations for all objects sharing that feature and coincides with when neurons select the singleton of a search array. This feature selectivity also reveals the distinct, subsequent operation of selecting the endpoint of the saccade in pro-saccade as well as anti-saccade trials. These results demonstrate that target selection preceding saccade preparation is composed of multiple operations. We conjecture that singleton selection indexes the allocation of attention, which can be divided, to conspicuous items. Consequently, endpoint selection indexes the focused allocation of attention to the endpoint of the saccade. These results demonstrate that saccade target selection is not a unitary process.SIGNIFICANCE STATEMENTFrontal eye field is well known to contribute to spatial selection for attention and eye movements. We discovered that some frontal eye field neurons can acquire selectivity for stimulus orientation when it guides visual search. The chronometry of neurons with and without feature selectivity reveal distinct operations accomplishing visual search.

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Faculty Opinions recommendation of Saccade target selection in the superior colliculus: a signal detection theory approach.

Faculty Opinions – Post-Publication Peer Review of the Biomedical Literature ◽

10.3410/f.1104754.560825 ◽

2008 ◽

Author(s):

Kathleen Cullen

Keyword(s):

Superior Colliculus ◽

Signal Detection ◽

Signal Detection Theory ◽

Target Selection ◽

Detection Theory ◽

Saccade Target ◽

Theory Approach

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Salience by Competitive and Recurrent Interactions: Bridging Neural Spiking and Computation

10.31234/osf.io/rkh8g ◽

2021 ◽

Author(s):

Gregory Edward Cox ◽

Thomas Palmeri ◽

Gordon D. Logan ◽

Philip L. Smith ◽

Jeffrey Schall

Keyword(s):

Decision Making ◽

Response Times ◽

Target Selection ◽

Interaction Model ◽

Saccade Target ◽

Frontal Eye Field ◽

Visual Neurons ◽

Discharge Rates ◽

Neural Spiking ◽

Eye Field

Decisions about where to move the eyes depend on neurons in Frontal Eye Field (FEF). Movement neurons in FEF accumulate salience evidence derived from FEF visual neurons to select the location of a saccade target among distractors. How visual neurons achieve this salience representation is unknown. We present a neuro-computational model of target selection called Salience by Competitive and Recurrent Interactions (SCRI), based on the Competitive Interaction model of attentional selection and decision making (Smith & Sewell, 2013). SCRI selects targets by synthesizing localization and identification information to yield a dynamically evolving representation of salience across the visual field. SCRI accounts for neural spiking of individual FEF visual neurons, explaining idiosyncratic differences in neural dynamics with specific parameters. Many visual neurons resolve the competition between search items through feedforward inhibition between signals representing different search items, some also require lateral inhibition, and many act as recurrent gates to modulate the incoming flow of information about stimulus identity. SCRI was tested further by using simulated spiking representations of visual salience as input to the Gated Accumulator Model of FEF movement neurons (Purcell et al., 2010; Purcell, Schall, Logan, & Palmeri, 2012). Predicted saccade response times fit those observed for search arrays of different set size and different target-distractor similarity, and accumulator trajectories replicated movement neuron discharge rates. These findings offer new insights into visual decision making through converging neuro-computational constraints and provide a novel computational account of the diversity of FEF visual neurons.

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