A computational model of selective deficits in first and second-order motion processing

Developing a widely accepted theory of behavior causation has been hampered by the lack of a rigorous approach to understanding the kinds of determinants at work. Interest in behavior change is also burgeoning, and requires a profound understanding of how personal and environmental determinants interact dynamically to predict changed behavioral outcomes. Behavior settings theory, a powerful naturalistic theory with a huge empirical underpinning, has long been available for describing the recurrent, everyday behavioral episodes in which many social and psychological scientists are interested. In this article, I review settings theory and update it in the light of a number of recent contributions from various quarters. I argue that this syncretic model should be seen as defining the proximate causal network surrounding these common behavioral episodes, which I call “situations.” I further propose that “contexts” should be thought of as the more distal, second-order causes circumscribing situations. I argue that these situational and contextual “spheres” of causation are a powerful way to understand behavior determination. I conclude by introducing a quasi-computational model of situations that is worthy of the further development necessary to make psychology a predictive science of behavioral causation and change.

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Common first- and second-order motion processing at high temporal frequencies

Journal of Vision ◽

10.1167/8.6.18 ◽

2010 ◽

Vol 8 (6) ◽

pp. 18-18 ◽

Cited By ~ 4

Author(s):

R. Allard ◽

J. Faubert

Keyword(s):

Second Order ◽

Motion Processing

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Form and motion processing of second-order stimuli in color vision

Journal of Vision ◽

10.1167/13.7.10 ◽

2013 ◽

Vol 13 (7) ◽

pp. 10-10

Author(s):

L. Garcia-Suarez ◽

K. T. Mullen

Keyword(s):

Color Vision ◽

Second Order ◽

Motion Processing

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The selective impairment of the perception of first-order motion by unilateral cortical brain damage

Visual Neuroscience ◽

10.1017/s0952523898152082 ◽

1998 ◽

Vol 15 (2) ◽

pp. 333-348 ◽

Cited By ~ 68

Author(s):

LUCIA M. VAINA ◽

NIKOS MAKRIS ◽

DAVID KENNEDY ◽

ALAN COWEY

Keyword(s):

Brain Damage ◽

Occipital Lobe ◽

Second Order ◽

Motion Processing ◽

First Order ◽

Cortical Level ◽

Unilateral Brain Damage ◽

Visual Hemifield ◽

Visual Area Mt ◽

Selective Impairment

First-order (Fourier) motion consists of stable spatiotemporal luminance variations. Second-order (non-Fourier) motion consists instead of spatiotemporal modulation of contrast, flicker, or spatial frequency. In spite of extensive psychophysical and computational analysis of the nature and relationship of these two types of motion, it remains unclear whether they are detected by the same mechanism or whether separate mechanisms are involved. Here we report the selective impairment of first-order motion, on a range of local and global motion tasks, in the contralateral visual hemifield of a patient with unilateral brain damage centered on putative visual areas V2 and V3 in the medial part of the occipital lobe. His perception of second-order motion was unimpaired. As his disorder is the obverse of that reported after damage in the vicinity of human visual area MT (V5), the results support models of motion processing in which first- and second-order motion are, at least in part, computed separately at the extrastriate cortical level.

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Processing of first-order motion in marmoset visual cortex is influenced by second-order motion

Visual Neuroscience ◽

10.1017/s0952523806230141 ◽

2006 ◽

Vol 23 (5) ◽

pp. 815-824 ◽

Cited By ~ 10

Author(s):

NICK BARRACLOUGH ◽

CHRIS TINSLEY ◽

BEN WEBB ◽

CHRIS VINCENT ◽

ANDREW DERRINGTON

Keyword(s):

Visual Cortex ◽

Low Frequency ◽

Second Order ◽

The Other ◽

Motion Processing ◽

Single Neurons ◽

First Order ◽

The Third ◽

Early Visual Cortex ◽

Direction Sensitivity

We measured the responses of single neurons in marmoset visual cortex (V1, V2, and the third visual complex) to moving first-order stimuli and to combined first- and second-order stimuli in order to determine whether first-order motion processing was influenced by second-order motion. Beat stimuli were made by summing two gratings of similar spatial frequency, one of which was static and the other was moving. The beat is the product of a moving sinusoidal carrier (first-order motion) and a moving low-frequency contrast envelope (second-order motion). We compared responses to moving first-order gratings alone with responses to beat patterns with first-order and second-order motion in the same direction as each other, or in opposite directions to each other in order to distinguish first-order and second-order direction-selective responses. In the majority (72%, 67/93) of cells (V1 73%, 45/62; V2 70%, 16/23; third visual complex 75%, 6/8), responses to first-order motion were significantly influenced by the addition of a second-order signal. The second-order envelope was more influential when moving in the opposite direction to the first-order stimulus, reducing first-order direction sensitivity in V1, V2, and the third visual complex. We interpret these results as showing that first-order motion processing through early visual cortex is not separate from second-order motion processing; suggesting that both motion signals are processed by the same system.

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