Optimizing the Representation of Orientation Preference Maps in Visual Cortex

The colorful representation of orientation preference maps in primary visual cortex has become iconic. However, the standard representation is misleading because it uses a color mapping to indicate orientations based on the HSV (hue, saturation, value) color space, for which important perceptual features such as brightness, and not just hue, vary among orientations. This means that some orientations stand out more than others, conveying a distorted visual impression. This is particularly problematic for visualizing subtle biases caused by slight overrepresentation of some orientations due to, for example, stripe rearing. We show that displaying orientation maps with a color mapping based on a slightly modified version of the HCL (hue, chroma, lightness) color space, so that primarily only hue varies between orientations, leads to a more balanced visual impression. This makes it easier to perceive the true structure of this seminal example of functional brain architecture.

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Heterogeneity in local distributions of orientation-selective neurons in the cat primary visual cortex

Visual Neuroscience ◽

10.1017/s095252380000818x ◽

1996 ◽

Vol 13 (3) ◽

pp. 509-516 ◽

Cited By ~ 28

Author(s):

Pedro E. Maldonado ◽

Charles M. Gray

Keyword(s):

Visual Cortex ◽

Primary Visual Cortex ◽

Local Level ◽

Spike Trains ◽

Preferred Orientation ◽

Orientation Tuning ◽

Area 17 ◽

Average Difference ◽

Orientation Preference ◽

Neuronal Spike Trains

AbstractWe have employed the tetrode technique, which allows accurate discrimination of individual neuronal spike trains from multiunit recordings, in order to examine the variation of orientation selectivity among local groups of neurons. We recorded a total of 321 cells from 62 sites in area 17 of halothane-anesthetized cats; each site contained between three to ten neurons that were estimated to be less than 65 μm away from the tetrode tip. For each cell, we determined the orientation tuning in response to moving bars. Of the cells tested, 8.4% were unresponsive, 22.7% had no preferential response to any particular orientation, while 68.8% were tuned. The average difference in preferred orientation between cell pairs recorded at the same site was 10.7 deg, but the variance in preferred orientation differences differed significantly among sites. Some clusters of cells exhibited the same or nearly the same orientation preference, while others had orientation preferences that differed by as much as 90 deg. Our data demonstrate that the tuning for orientation is more heterogeneously distributed at a local level than previous studies have suggested.

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Establishment of a Scaffold for Orientation Maps in Primary Visual Cortex of Higher Mammals

Journal of Neuroscience ◽

10.1523/jneurosci.5514-06.2008 ◽

2008 ◽

Vol 28 (1) ◽

pp. 249-257 ◽

Cited By ~ 21

Author(s):

A. Grabska-Barwinska ◽

C. von der Malsburg

Keyword(s):

Visual Cortex ◽

Primary Visual Cortex ◽

Orientation Maps

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The Joint Development of Orientation and Ocular Dominance: Role of Constraints

Neural Computation ◽

10.1162/neco.1997.9.5.959 ◽

1997 ◽

Vol 9 (5) ◽

pp. 959-970 ◽

Cited By ~ 16

Author(s):

Christian Piepenbrock ◽

Helge Ritter ◽

Klaus Obermayer

Keyword(s):

Visual Cortex ◽

Primary Visual Cortex ◽

Ocular Dominance ◽

Receptive Fields ◽

Simple Cell ◽

Orientation Preference ◽

Joint Development ◽

Independent Work ◽

Insight Into

Correlation-based learning (CBL) has been suggested as the mechanism that underlies the development of simple-cell receptive fields in the primary visual cortex of cats, including orientation preference (OR) and ocular dominance (OD) (Linsker, 1986; Miller, Keller, & Stryker, 1989). CBL has been applied successfully to the development of OR and OD individually (Miller, Keller, & Stryker, 1989; Miller, 1994; Miyashita & Tanaka, 1991; Erwin, Obermayer, & Schulten, 1995), but the conditions for their joint development have not been studied (but see Erwin & Miller, 1995, for independent work on the same question) in contrast to competitive Hebbian models (Obermayer, Blasdel, & Schulten, 1992). In this article, we provide insight into why this has been the case: OR and OD decouple in symmetric CBL models, and a joint development of OR and OD is possible only in a parameter regime that depends on nonlinear mechanisms.

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