Related Experiment Video
Updated: Mar 26, 2026

09:49
Methods to Explore the Influence of Top-down Visual Processes on Motor Behavior
Published on: April 16, 2014
27.0K
A Note on the Horizontal-Vertical Illusion - A Reply to Wade (2014).
1Johannes Gutenberg-Universität Mainz, Germany.
Perception
|January 31, 2016
Summary
This study corrects historical inaccuracies regarding Adolf Fick's 1851 dissertation and its associated visual illusion figures. Fick's foundational work on the horizontal-vertical illusion has been largely overlooked in modern research.
Area of Science:
- Vision science
- History of science
Background:
- Nicholas Wade incorrectly cited Adolf Fick's dissertation title and attributed specific illusion figures to him.
- The horizontal-vertical illusion figures (e.g., +, L, inverted T) are widely recognized but their attribution has been historically inaccurate.
Purpose of the Study:
- To correct the historical record concerning Adolf Fick's 1851 dissertation and its associated visual illusions.
- To re-evaluate the significance of Fick's early contributions to the understanding of visual perception.
Main Methods:
- Historical document verification of Adolf Fick's dissertation title and university.
- Comparative analysis of historical attributions of visual illusion figures.
Main Results:
- Adolf Fick's dissertation title and the correct attribution of the horizontal-vertical illusion figures have been identified.
- Previous attributions by Nicholas Wade were found to be erroneous.
Conclusions:
- Fick's original work on the horizontal-vertical illusion, despite its historical significance, has been neglected in contemporary vision science.
- Accurate historical attribution is crucial for understanding the progression of scientific thought in visual perception.
More Related Videos
Related Concept Videos
Masonry Curtain Walls
2.2K
Masonry curtain walls employ brick or stone veneers supported by the building's structure to form an external cladding system that is both aesthetically appealing and functional. These walls are erected through two principal techniques, first by traditional layering of masonry units and second by using prefabricated panels. Traditional construction relies on steel shelf angles attached to the spandrel beam for support, with high-bond mortars ensuring secure attachment of masonry veneer...
2.2K
Masonry Loadbearing Walls
533
Masonry load-bearing walls, constructed from materials like brick, stone, or concrete masonry units, serve as a crucial component in building structures by supporting the loads from floors and roofs and transferring them to the foundation. These walls, known for their compressive strength, can be reinforced or unreinforced to suit different building needs, accommodating both the dead and live loads while maintaining safety through lower working stresses compared to the materials' ultimate...
533
Posttensioned Masonry Walls
575
Post-tensioned masonry walls use high-strength steel rods or flexible tendons to enhance the strength and efficiency of masonry structures. These elements are securely anchored to the foundation and extend vertically either within the cores of the masonry units or between the masonry wythes. The construction process involves building the wall with these tensioning elements in place and allowing the mortar to fully cure.
Following the curing process, the tensioning begins. Steel rods are...
575
Composite Masonry Walls
2.2K
Composite masonry walls combine multiple wythes of the same or different masonry materials to create a unified structure. These walls feature wythes that are bonded together either through mortar-filled collar joints, grouted spaces, or more commonly, with rigid metal ties and reinforcements, with the use of masonry header units being rare. Metal ties are preferred because they effectively minimize water penetration, as these walls primarily absorb moisture and then release it into the...
2.2K
Masonry Cavity Walls
1.8K
Cavity walls feature a hollow space between the outer and inner wythes, connected only by corrosion-resistant metal ties. When water seeps through the outer wythe, it descends within this cavity, intercepted by flashing and eventually exiting through weep holes. To enhance moisture resistance, the inner wythe's cavity side often receives damp-proofing, doubling as an air barrier. The cavity can also house insulation to mitigate heat transfer.
Maintaining a clean cavity during construction...
Maintaining a clean cavity during construction...
1.8K
Sight Distance in a Vertical Curve
471
Sight distance on vertical curves is critical in roadway design. It ensures drivers can see far enough ahead to identify and respond to hazards effectively. This directly impacts safety, driver comfort, and the overall efficiency of the transportation network.Vertical curves are classified into crest and sag curves based on their geometry. For crest curves, sight distance is determined by the line of sight between a driver's eye and a small object on the road's surface. Design parameters for...
471

