Functional fixedness in tool use: Learning modality, limitations and individual differences.

Functional fixedness is a cognitive bias that describes how previous knowledge of a tool's function can negatively impact the use of this tool in novel contexts. As such, functional fixedness disturbs the use of tools during mechanical problem solving. Little is known about whether this bias emerges from different experiences with tools, whether it occurs regardless of problem difficulty, or whether there are protective factors against it. To resolve the first issue, we created five experimental groups: Reading (R), Video (V), Manual (M), No Functional Fixedness (NFF), and No Training (NT). The R group learned to use tools by reading a description of their use, the V group by watching an instructional video, and the M group through direct instruction and active manipulation of the tools. To resolve the remaining two issues, we created mechanical puzzles of distinct difficulty and used tests of intuitive physics, fine motor skills, and creativity. Results showed that misleading functional knowledge is at the core of functional fixedness, and that this bias generates cognitive impasses in simple puzzles, but it does not play a role in higher difficulty problems. Additionally, intuitive physics and motor skills were protective factors against its emergence, but creativity did not influence it. Although functional fixedness leads to inaccurate problem solving, our results suggest that its effects are more limited than previously assumed.

Simultaneous fundus imaging and optical coherence tomography of the mouse retina.

PURPOSE: To develop a retinal imaging system suitable for routine examination or screening of mouse models and to demonstrate the feasibility of simultaneously acquiring fundus and optical coherence tomography (OCT) images. METHODS: The imaging system is composed of a photographic slit lamp for biomicroscopic examination of the fundus, an OCT interferometer, an OCT beam delivery system designed for the mouse eye, and a mouse positioning stage. Image acquisition was controlled with software that displays the fundus and OCT images in real time, and allows the user to control the position of the OCT beam spot on the fundus image display. The anesthetized mouse was placed in a cylindrical holder on the positioning stage, and a single operator adjusted the position of mouse. RESULTS: Fundus images and OCT scans were successfully acquired in both eyes of 8 C57BL/6 mice. Once the animal is anesthetized and placed in the holder, a typical imaging experiment takes less than 2 minutes. The retinal vasculature, pigmentation, nerve fiber arrangement, and optic nerve head were clearly visible on the fundus images. The quality of the OCT images was sufficient to allow measurement of the total, inner, and outer retinal thicknesses and to visualize the optic nerve head excavation. CONCLUSIONS: The study demonstrates the feasibility of acquiring simultaneous fundus and OCT images of the mouse retina, by a single operator, in a manner suitable for routine evaluation of mouse models of retinal disease.