An investigation of far and near transfer in a gamified visual learning paradigm

Abstract

After training, visual perceptual learning improvements are mostly constrained to the trained stimulus feature and retinal location. The aim of this study is to construct an integrated paradigm where the visual learning happens in a more natural context and in parallel for multiple stimulus types, and to test the generalization of learning-related improvements towards untrained features, locations, and more general cognitive domains. Half the subjects were trained with a gamified perceptual learning paradigm for ten hours, which consisted of an orientation discrimination task and a novel object categorization task embedded in a three-dimensional maze. A second group of subjects, an active control group, played ten hours of Candy Crush Saga. Before and after training, all subjects completed a 'near transfer' orientation discrimination and novel object categorization task, as well as a set of 'far transfer' general cognitive and attentional tasks. During the perceptual learning tasks, two different stimulus features and two retinal location pairs were assessed in each task. For the experimental group, one stimulus feature and retinal location pair was trained, whilst the other one remained untrained. Both features and location pairs were untrained in the control group. Far transfer did occur in some domains across all subjects irrespective of the training regimen (i.e. executive functioning, mental rotation performance, and multitask performance and speed). Near transfer was present in both groups, however only more pronounced for one particular task in the experimental group, namely novel object categorization. To conclude, all but one near transfer task did not generalize more than the control group.

Fig 1. Screenshots from the game.

(A) The main screen where subjects can start the game, read the instructions, look at their achievements or exit the game. (B) There are six different achievement pages regarding: collected cues, and coins, traveled maze distance, killed rats, and reached levels. Within each achievement, there are six different degrees: novice, advanced beginner, competent, proficient, expert, and boss. (C) At the start of each level, the subject is dropped somewhere in the maze. (D) Screenshot during the game. The pink-grey boxes represent the cues. After collection each cue was predictive (i.e. 70% probability) of the identity of the next stimuli. For example, when participating in the orientation discrimination task, two dots were likely followed by a clockwise rotation. Right before stimulus onset the white fixation turns red and subjects could not navigate. (E) Screenshot during stimulus presentation during which the subject could not navigate and had time to make a response. (F) The subject is punished for not responding or responding incorrectly and (G) rewarded for answering correctly. (H) During the game, the player received some knowledge on this position in the maze by means of the little room underneath the fixation cross, which only shows the nearby room(s) and collectibles.

Fig 2. An overview of the perceptual stimuli, tasks, and retinal locations.

(A) Demonstration of both object types (smoothies and cubies) and their subdivision between a category one and two object type. (B) Illustration of the 0 and 90 degrees Gabor references on the left and the task on the right. (C) Graphical display on the left of the left-right location pair, and above-below location pair on the right.

Fig 3. A visual timeline infographic of the study.

Fig 4

A summary of the perceptual learning thresholds during the game in the novel object categorization task (A) and orientation discrimination task (B). The error bars represent the standard error across all subjects for the average number of finished staircase. The green line represents the learning slope across subjects over the average number of staircases.

Fig 5. A summary of the near transfer results.

The mean threshold in each condition and across all conditions before and after training in the novel object categorization task (A-B) and the orientation discrimination task (C-D). obj1/ori1 = trained stimulus, obj2/ori2 = untrained stimulus, ori1 = trained location pair, ori2 = untrained location pair, obj/ori = trained and untrained conditions together, and loc = trained and untrained location pairs together. Error bars represent the standard error of the mean across participants. A significant difference between pre- and post-training is marked as * p < .05, ** p < .01, and *** p < .001.