Our aim was to confirm that vision in adults can be trained to associate certain retinal locations with specific depth arrangements of stimuli, such that presenting a depth-ambiguous stimulus at a certain retinal location would cause it to be perceived to have a specific depth arrangement. Even if Backus et al. have already demonstrated that "cue-recruitment" is still possible in human adults, i.e. that adults can still learn to associate any arbitrary stimulus feature with depth, we were not able to verify the hypothesis that our ability to perceive depth is not innate and - thus - purely a product of postnatal learning experience, whereby the capacity is still present in human adults. We verified that the 14 subjects could reliably report depth as a group, but they did not perceive, more than would be expected by chance, the same depth arrangement for an ambiguous stimulus at a particular location in the test block as they had for the unambiguous stimuli at that location in the training blocks. Hence, we rejected the first H_{0, training} hypothesis that there is no significant difference in the number of correct and incorrect answers during the training session, and furthermore, retained the second H_{0, test} hypothesis that there is no significant difference between the number of trials, in which a test block was perceived to be same or opposite to the previous training stimuli at the respective same location as in the training trials, since the paired t-test gave rise to t(13)_{0.05}=0.2 , which is well below the expected value for a one-tailed t-test of 1.7.
Table of Contents
1. Introduction
2. Methods
3. Results
4. Discussion
5. Conclusion
Objectives and Topics
The research investigates whether human adults possess the capacity to learn new cues for depth perception through associative training, building upon the concept of cue-recruitment. The study aims to determine if vision in adults remains modifiable by training specific retinal locations to associate with particular depth arrangements.
- Sensory motor development and perceptual plasticity
- Cue-recruitment mechanisms in adult subjects
- Experimental analysis of depth perception learning
- Evaluation of retinal location-based depth association
Excerpt from the Book
1. Introduction
One of the classical debates in psychology is to what extent our ability to perceive the world is biologically-predetermined versus the product of postnatal experience. Infant perception cannot be measured directly, but indirect measures such as physiological and behavioural ones are possible. Perception of depth has been investigated by the “visual cliff” paradigm – first used by Gibson and Walk [1]. Infants of crawling age, around 7 months upward, were placed on a dark surface next to a transparent sheet of safety glass at a height of about 1m above the floor, and were incentivised by their mothers to crawl across it. Only very few did, but when put on the transparent safety glass, they happily crawled over, which leads to the assumption that these infants could accurately interpret the depth cues. Even younger infants showed a change in heart rate, when held over the different parts in the experimental setup of the “visual cliff”. [3] At this age, they can already distinguish different depths, but only learn to appreciate fully what they “mean” once they gain locomotor experience.
Hence, human infants seem to learn which cues in the visual input signal depth. The question we are addressing here is whether this ability to learn new cues to depth is still present in human adults? Backus et al. [2] have shown that adults can learn to associate any arbitrary stimulus feature with depth and that these features by themselves would elicit depth perception. In this experimental design, our aim is to confirm that vision in adults is still modifiable by association training of specific retinal locations with certain depth arrangements of stimuli, such that the presentation of a depth-ambiguous stimulus at a particular location would cause it to be perceived as having a certain depth arrangement.
Summary of Chapters
1. Introduction: Outlines the debate between innate versus learned depth perception and establishes the research goal of testing adult visual plasticity through cue-recruitment.
2. Methods: Describes the experimental procedure involving a depth discrimination task where participants were trained to associate specific retinal locations with depth cues using fixation crosses and rectangles.
3. Results: Details the statistical analysis of the training and test blocks, noting that while participants reliably reported depth during training, no significant learning effect was observed in the ambiguous test phase.
4. Discussion: Evaluates the experimental design, noting limitations such as the two-alternative forced choice task and suggesting improvements for future research.
5. Conclusion: Summarizes the findings, confirming the rejection of the null hypothesis for training performance while retaining the null hypothesis regarding depth perception learning in the ambiguous test blocks.
Keywords
Sensory motor development, Plasticity, Depth perception, Cue-recruitment, Visual cliff, Adult perception, Retinal location, Postnatal learning, Binocular disparity, Stimulus association, Experimental psychology, Perception training, Depth discrimination, Ambiguous stimuli, Visual perception.
Frequently Asked Questions
What is the core subject of this research paper?
The paper explores sensory motor development and whether adult vision retains the plasticity required to learn new cues for depth perception.
What are the central thematic fields addressed?
The research focuses on developmental psychology, specifically the interaction between innate visual abilities and postnatal experience through cue-recruitment.
What is the primary goal of the study?
The goal is to determine if adults can be trained to perceive depth in ambiguous stimuli by associating specific retinal locations with depth arrangements learned during training.
Which scientific methodology was utilized?
The study utilized a depth discrimination task with training blocks of unambiguous stimuli followed by a test block containing ambiguous stimuli, analyzed using paired t-tests.
What is covered in the main body of the text?
The main body covers the theoretical background of the visual cliff paradigm, the detailed experimental method, the statistical results of the training and test phases, and a critical discussion of the study's design.
Which keywords best characterize this work?
Key terms include sensory motor development, plasticity, depth perception, cue-recruitment, and associative learning.
Why were the two groups of participants (Group A and B) merged?
They were collapsed into a single group because there was a lack of observers reporting consistent depth perception during the training trials.
Why did the author conclude that the results were unexpected?
The results were unexpected because the study failed to replicate the findings of Backus et al., showing that adults did not perceive the depth arrangement of ambiguous stimuli as predicted by the training.
What specific suggestion does the author make to improve the experiment?
The author suggests adding a confidence scale or a "Don't know" option to the forced-choice task to prevent guessing and improve data accuracy.
- Arbeit zitieren
- Laura Imperatori (Autor:in), 2014, Sensory Motor Development and Plasticity, München, GRIN Verlag, https://www.grin.com/document/276479
