Spatiotemporal Dynamics of Attention-Induced Distortions and Illusions

Perception ◽  
1997 ◽  
Vol 26 (1_suppl) ◽  
pp. 54-54
Author(s):  
M H Yoo ◽  
J Schelchshorn ◽  
C S Chung ◽  
R Sireteanu
Keyword(s):  
Receptive Field ◽  
Human Perception ◽  
Stimulus Presentation ◽  
Line Length ◽  
Staircase Method ◽  
Temporal Properties ◽  
Field Shift ◽  
Line Tilt ◽  
Induced Changes ◽  
Shift Hypothesis

Selective attention induces perceptual distortions, ranging from repulsion of objects located near the attended area (Suzuki and Cavanagh, 1994 Investigative Ophthalmology and Visual Science35 2081) to magnification of inattended objects (Tsal and Shalev, 1996 Journal of Experimental Psychology: Human Perception and Performance22 233 – 243). Two hypothetical mechanisms have been postulated: a shift of receptive field positions away from the locus of attention (receptive-field shift hypothesis) or the enlargement of perceived space around the attended location (spatial-enlargement hypothesis). The aim of the present study was to distinguish between these two hypotheses, by investigating the spatial and temporal properties of attention-induced distortions. Perceptual judgments on Vernier alignment, line tilt, line length, and size of outlined figures were used to measure attention-induced changes in perception. Attention was induced exogenously (by blinking a specific set of dots around the test stimuli) or endogenously (by instructing the subject to selectively attend the dots). After inducing attention, the test stimuli were briefly flashed. A staircase method was used to measure the attentional effect. The experiment was performed with 3 Korean and 3 German subjects. A vertical line was perceived as repelled from the locus of attention, and a line segment appeared longer when attention was given to its vicinity. In addition, several well-known illusions (eg the Ponzo and the Gibson illusions) were produced by having the subjects merely attend a set of inducing dots. The effects decreased as the distance between the locus of attention or the time between the onset of attention and the stimulus presentation increased. The results imply that the space-enlargement hypothesis provides a better explanation for the attention-induced changes in perception than the receptive-field-shift hypothesis.

Bayesian Inference in Human Time Perception

2017 ◽  
Author(s):  
Darren Rhodes
Keyword(s):  
Time Perception ◽  
Likelihood Function ◽  
Human Perception ◽  
Future Research ◽  
Temporal Properties ◽  
History Of Research ◽  
Psychophysical Testing ◽  
History Of ◽  
Fundamental Dimension ◽  
Perception Of Time

Time is a fundamental dimension of human perception, cognition and action, as the perception and cognition of temporal information is essential for everyday activities and survival. Innumerable studies have investigated the perception of time over the last 100 years, but the neural and computational bases for the processing of time remains unknown. First, we present a brief history of research and the methods used in time perception and then discuss the psychophysical approach to time, extant models of time perception, and advancing inconsistencies between each account that this review aims to bridge the gap between. Recent work has advocated a Bayesian approach to time perception. This framework has been applied to both duration and perceived timing, where prior expectations about when a stimulus might occur in the future (prior distribution) are combined with current sensory evidence (likelihood function) in order to generate the perception of temporal properties (posterior distribution). In general, these models predict that the brain uses temporal expectations to bias perception in a way that stimuli are ‘regularized’ i.e. stimuli look more like what has been seen before. Evidence for this framework has been found using human psychophysical testing (experimental methods to quantify behaviour in the perceptual system). Finally, an outlook for how these models can advance future research in temporal perception is discussed.

scholarly journals Distinguishing Hemodynamics from Function in the Human LGN Using a Temporal Response Model

Vision ◽  
2019 ◽  
Vol 3 (2) ◽  
pp. 27 ◽  
Author(s):  
Kevin DeSimone ◽  
Keith A. Schneider
Keyword(s):  
Receptive Field ◽  
Visual Processing ◽  
Field Model ◽  
Ventral Surface ◽  
Impulse Response Functions ◽  
Response Model ◽  
Response Functions ◽  
Temporal Response ◽  
Point Of Entry ◽  
Temporal Properties

We developed a temporal population receptive field model to differentiate the neural and hemodynamic response functions (HRF) in the human lateral geniculate nucleus (LGN). The HRF in the human LGN is dominated by the richly vascularized hilum, a structure that serves as a point of entry for blood vessels entering the LGN and supplying the substrates of central vision. The location of the hilum along the ventral surface of the LGN and the resulting gradient in the amplitude of the HRF across the extent of the LGN have made it difficult to segment the human LGN into its more interesting magnocellular and parvocellular regions that represent two distinct visual processing streams. Here, we show that an intrinsic clustering of the LGN responses to a variety of visual inputs reveals the hilum, and further, that this clustering is dominated by the amplitude of the HRF. We introduced a temporal population receptive field model that includes separate sustained and transient temporal impulse response functions that vary on a much short timescale than the HRF. When we account for the HRF amplitude, we demonstrate that this temporal response model is able to functionally segregate the residual responses according to their temporal properties.

Temporal Oscillations in Human Perception

1993 ◽  
Vol 4 (4) ◽  
pp. 264-270 ◽  
Author(s):  
Stanislas Dehaene
Keyword(s):  
Task Difficulty ◽  
Response Times ◽  
Human Perception ◽  
Stimulus Presentation ◽  
Human Response ◽  
Time Intervals ◽  
Discrete Processing ◽  
Processing Steps ◽  
Continuous Accumulation

The notion that human perceptual decisions are based on discrete processing cycles rather than a continuous accumulation of information was examined experimentally. Significant periodicities were found in human response times (RT) to feature and conjunction discrimination tasks in the visual and auditory modalities. Individual RT histograms were multimodal, with regularly spaced peaks and troughs, indicating that responses were emitted more frequently at regularly recurring time intervals following stimulus presentation. On average, responses were initiated after four to seven discrete processing steps whose “quantum” duration was proportional to task difficulty.

scholarly journals Unifying Temporal Phenomena in Human Visual Cortex

2017 ◽  
Author(s):  
Jingyang Zhou ◽  
Noah C. Benson ◽  
Kendrick Kay ◽  
Jonathan Winawer
Keyword(s):  
Visual Cortex ◽  
Receptive Field ◽  
Temporal Dynamics ◽  
Gain Control ◽  
Spatial Vision ◽  
Research Area ◽  
Neuronal Responses ◽  
Stimulus Contrast ◽  
Temporal Properties ◽  
Cortical Responses

AbstractNeuronal responses in visual cortex show a diversity of complex temporal properties. These properties include sub-additive temporal summation, response reduction with repeated or sustained stimuli (adaptation), and slower dynamics at low stimulus contrast. Here, we hypothesize that these seemingly disparate effects can be explained by a single, shared computational mechanism. We propose a model consisting of a linear stage, followed by history-dependent gain control. The model accounts for these various temporal phenomena, tested against an unusually diverse set of measurements - intracranial electrodes in patients, fMRI, and macaque single unit spiking. The model further enables us to uncover a systematic and rich variety of temporal encoding strategies across visual cortex: First, temporal receptive field shape differs both across and within visual field maps. Second, later visual areas show more rapid and pronounced adaptation. Our study provides a new framework to understand the transformation between visual input and dynamical cortical responses.Author SummaryThe nervous system extracts meaning from the distribution of light over space and time. Spatial vision has been a highly successful research area, and the spatial receptive field has served as a fundamental and unifying concept that spans perception, computation, and physiology. While there has also been a large interest in temporal vision, the temporal domain has lagged the spatial domain in terms of quantitative models of how signals are transformed across the visual hierarchy. Here we present a model of temporal dynamics of neuronal responses in human cerebral cortex. We show that the model can accurately predict responses at the millisecond scale using intracortical electrodes in patient volunteers, and that the same model generalizes to multiple types of other measurements, including functional MRI and action potentials from monkey cortex. Further, we show that a single model can account for a variety of temporal phenomena, including short-term adaptation and slower dynamics at low stimulus contrast. By developing a computational model and showing that it successfully generalizes across measurement types, cortical areas, and stimuli, we provide new insights into how time-varying images are encoded and transformed into dynamic cortical responses.

Asymmetric Temporal Properties in the Receptive Field of Transient Amacrine Cells in Carp Retina

2003 ◽  
pp. 117-117
Author(s):  
Masahiro Yamada ◽  
Masanori Iwasaki ◽  
Tetsuo Furukawa ◽  
Syozo Yasui ◽  
Kaj Djupsund
Keyword(s):  
Receptive Field ◽  
Amacrine Cells ◽  
Temporal Properties

Focal attention produces spatially selective processing in visual cortical areas V1, V2, and V4 in the presence of competing stimuli

1993 ◽  
Vol 70 (3) ◽  
pp. 909-919 ◽  
Author(s):  
B. C. Motter
Keyword(s):  
Receptive Field ◽  
Stimulus Presentation ◽  
Spatial Location ◽  
Differential Sensitivity ◽  
Orientation Tuning ◽  
Area V4 ◽  
Focal Attention ◽  
V4 Neurons ◽  
Visual Cortical ◽  
Competing Stimuli

1. The activity of single neurons was recorded in Macaca mulatta monkeys while they performed tasks requiring them to select a cued stimulus from an array of three to eight stimuli and report the orientation of that stimulus. Stimuli were presented in a circular array centered on the fixation target and scaled to place a single stimulus element within the receptive field of the neuron under study. The timing of the cuing event permitted the directing of visual attention to the spatial location of the correct stimulus before its presentation. 2. The effects of focal attention were examined in cortical visual areas V1, V2, and V4, where a total of 672 neurons were isolated with complete studies obtained for 94 V1, 74 V2, and 74 V4 neurons with receptive-field center eccentricities in the range 1.8-8 degrees. Under certain conditions, directed focal attention results in changes in the response of V1, V2, and V4 neurons to otherwise identical stimuli at spatially specific locations. 3. More than one-third of the neurons in each area displayed differential sensitivity when attention was directed toward versus away from the spatial location of the receptive field just before and during stimulus presentation. Both relative increases and decreases in neural activity were observed in association with attention directed at receptive-field stimuli. 4. The presence of multiple competing stimuli in the visual field was a major factor determining the presence or absence of differential sensitivity. About two-thirds of the neurons that were differentially sensitive to the attending condition in the presence of competing stimuli were not differentially sensitive when single stimuli were presented in control studies. For V1 and V2 neurons the presence of only a few (3-4) competing stimuli was sufficient for a majority of the neurons studied; a majority of the V4 neurons required six to eight stimuli in the array before significant differences between attending conditions occurred. 5. For V1 and V2 neurons the neuronal sensitivity differences between attending conditions were observed primarily at or near the peak of the orientation tuning sensitivity for each neuron; the differences were evident over a broader range of orientations in V4 neurons. 6. In conclusion, neural correlates of focal attentive processes can be observed in visual cortical processing in areas V1 and V2 as well as area V4 under conditions that require stimulus feature analysis and selective spatial processing within a field of competing stimuli.(ABSTRACT TRUNCATED AT 400 WORDS)

Matched filtering in the visual system of the fly : large monopolar cells of the lamina are optimized to detect moving edges and blobs

1990 ◽  
Vol 240 (1298) ◽  
pp. 279-293 ◽  
Keyword(s):  
Receptive Field ◽  
Receptive Fields ◽  
High Light ◽  
Vertical Stripe ◽  
Ambient Light ◽  
Low Light ◽  
Temporal Properties ◽  
Light Levels ◽  
Spatio Temporal ◽  
Temporal Inhibition

At high levels of ambient light, large monopolar cells (LMCS) display spatially antagonistic receptive fields and a biphasic response to a brief flash of light from an axially positioned point source. In low ambient light the response becomes monophasic everywhere within the receptive field. Using the theory of matched filters, we infer that the LMCS are optimal for the detection of moving edges at high light levels, and for ‘blobs’ in low ambient light. The spatio-temporal properties predicted by the theory are in agreement with experimental observation. At high light levels, the strong temporal inhibition, the weak, diffuse lateral inhibition, and the non-separability of the receptive field in space and time are all properties that promote the sensitivity to a moving edge. At low light levels, the lack of spatial or temporal antagonism enhances the sensitivity to a blob. Our hypothesis is reinforced by the observation that flies tend to walk toward the edges of a broad, dark vertical stripe at high light levels, but uniformly toward all regions within the stripe in low ambient light.

Response to Motion in Extrastriate Area MSTl: Center-Surround Interactions

1998 ◽  
Vol 80 (1) ◽  
pp. 282-296 ◽  
Author(s):  
Satoshi Eifuku ◽  
Robert H. Wurtz
Keyword(s):  
Receptive Field ◽  
Opposite Direction ◽  
Visual Motion ◽  
Stimulus Presentation ◽  
Macaque Monkey ◽  
Object Motion ◽  
Temporal Area ◽  
Field Center ◽  
Preferred Direction ◽  
Receptive Field Center

Eifuku, Satoshi and Robert H. Wurtz. Response to motion in extrastriate area MSTl: center-surround interactions. J. Neurophysiol. 80: 282–296, 1998. The medial superior temporal area of the macaque monkey extrastriate visual cortex can be divided into a dorsal medial (MSTd) and a lateral ventral (MSTl) region. The functions of the two regions may not be identical: MSTd may process optic flow information that results from the movement of the observer, whereas MSTl may be related more closely to processing visual motion related specifically to the motion of objects. If MSTl were related to such object motion, one would expect to see mechanisms for the segregation of objects from their surround. We investigated one of these mechanisms in MSTl neurons: the effect of stimuli falling in the region surrounding the receptive field center on the response to stimuli falling in the field center. We found the effects of the surround stimulation to be modulatory with little response to the surround stimulus itself but a clear effect on the response to the stimulus falling on the receptive field center. The response to motion in the center in the direction preferred for the neuron usually increased when the surround motion was in the opposite direction to that in the center and decreased when surround motion was in the same direction as that in the center. Fifty-seven percent of the neurons showed a ratio of response for center motion with a surround moving in the opposite direction to that in the center for center motion alone that was >1. The response to motion in the center also increased when the surround stimulus was stationary, and this increase was sometimes larger than that with a moving surround. Nearly 70% of the neurons showed a ratio of response to center motion with a stationary surround to center motion alone that was >1. This is in contrast to the minimal effect of stationary surrounds in middle temporal area neurons. When the stimulus presentation was reversed so that the stimulus in the center was stationary and the surround moved, some MSTl neurons responded when the direction of motion in the surround was in the direction opposite to the preferred direction of motion in the center of the receptive field. Stimulation of the surround thus had a profound effect on the response of MSTl neurons, and this pronounced effect of the surround is consistent with a role in the segmentation of objects using motion.

Visual and presaccadic neuronal activity in thalamic internal medullary lamina of cat: a study of targeting

1977 ◽  
Vol 40 (1) ◽  
pp. 156-173 ◽  
Author(s):  
M. Schlag-Rey ◽  
J. Schlag
Keyword(s):  
Eye Movements ◽  
Receptive Field ◽  
Eye Movement ◽  
Receptive Fields ◽  
Stimulus Presentation ◽  
Visual Responses ◽  
Stimulus Movement ◽  
The Gaze ◽  
Double Activation ◽  
Alert Cats

1. Visual responses and eye movement-related activities were studied in single neurons of the thalamic internal medullary lamina (IML) of alert cats. The animals faced a tangent screen on which stationary or moving spots of light were presented. Of 95 units, 26% discharged in relation to photic stimuli but not eye movement, 6% in relation to eye movement but not photic stimuli, and 68% in relation to both. These units were intermixed in the same region. 2. Visual responses varied from transient to sustained. IML units were not found particularly sensitive to stimulus movement when the eyes were fixed. Strong and consistent responses could be elicited by extremely dim and weakly contrasted stationary stimuli (e.g.) 3.4 mcd/m2, 2.6% of illumination background) binocularly viewed. Receptive fields (from 250 to 800 deg2) were determined, in absence of eye movements, by computing the position of effective stimuli relative to the point of fixation of the gaze. An area of greatest responsiveness in the receptive field of most units could be detected on the basis of either higher probability of response, minimum latency, greater number of spikes in initial transient burst, or stronger sustained activity. Whole fields or their areas of greatest responsiveness were located on the side toward which saccades were accompanied by increased firing of the unit. 3. On trials in which a delay occurred between stimulus presentation and the cat's targeting saccade, the majority of the units studied changed their activity twice: after the stimulus and before the eye movement. In 16 units, the presaccadic activation occurred only with targeting, not with spontaneous saccades. 4. These results suggest that cells in the IML region of the cat play a significant role in the control of visually elicited eye movements. The resemblance of these cells to the monkey's tectual cells is discussed and hypotheses are proposed a) to relate the receptive field characteristics to the targeting operation, and b) to account for the double activation--sensory and motor--of many IML cells.

scholarly journals On the Distinction Between Perceived Duration and Event Timing: Towards a Unified Model of Time Perception

2018 ◽  
Vol 6 (1) ◽  
pp. 90-123 ◽  
Author(s):  
Darren Rhodes
Keyword(s):  
Time Perception ◽  
Likelihood Function ◽  
Human Perception ◽  
Unified Model ◽  
Temporal Properties ◽  
Event Timing ◽  
Fundamental Dimension ◽  
Perception Of Time ◽  
The Brain ◽  
Perceived Duration

Time is a fundamental dimension of human perception, cognition and action, as the processing and cognition of temporal information is essential for everyday activities and survival. Innumerable studies have investigated the perception of time over the last 100 years, but the neural and computational bases for the processing of time remains unknown. Extant models of time perception are discussed before the proposition of a unified model of time perception that relates perceived event timing with perceived duration. The distinction between perceived event timing and perceived duration provides the current for navigating a river of contemporary approaches to time perception. Recent work has advocated a Bayesian approach to time perception. This framework has been applied to both duration and perceived timing, where prior expectations about when a stimulus might occur in the future (prior distribution) are combined with current sensory evidence (likelihood function) in order to generate the perception of temporal properties (posterior distribution). In general, these models predict that the brain uses temporal expectations to bias perception in a way that stimuli are ‘regularized’ i.e. stimuli look more like what has been seen before. As such, the synthesis of perceived timing and duration models is of theoretical importance for the field of timing and time perception.

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