Moderators and Mediators of Perceptual Learning
ConditionCognitive Change
Trial statusRecruiting
Trial phaseNot applicable
Trial typeInterventional
Biological sexAll
Age18-85
SponsorUniversity of Wisconsin, Madison
About this trial
This is a research study about how training can impact performance on cognitive tasks. Participants are between 18 and 30 and 60 to 85 years of age, have normal (or corrected to normal) vision, and have no neurological conditions that would preclude their ability to complete computerized cognitive tasks. Up to 1140 participants will be on study for up to 8 weeks.
Eligibility criteria
This trial accepts healthy volunteersQualifiers
between18 and 30 years of age (younger cohort)
between 60 and 85 years of age (older cohort)
Corrected vision of 20/40 or better (as assessed with an eye chart)
No reported incidence of retinal pathology or neurological disease
Disqualifiers
Corrected vision of 20/40 or worse
Evidence of retinal pathology or retinal disease
Trial design
Design model
Parallel
Treatments tested in this trial
C1 - Standard Perceptual Learning (SPL)
BehavioralEach trial starts with a fixation point (500ms) after which a Gabor (1° radius, at cut-off SF of 25% accuracy, estimated from Pre-Test CSF, at either 45° or 135°) appears for 128ms. The task is to indicate whether the Gabor was tilted left or right. Gabor contrast will be controlled by a 3/1 staircase (converging on approximately \~80% contrast threshold) across all training sessions.
C2 - Long Training (LT)
BehavioralWill be the same as the SPL with the exception that each session in LT will be twice as long as in SPL.
C3 - Short Staircases (SS)
BehavioralWill be largely the same as SPL with the only difference being a change to the adaptive procedure. SS will use so-called "short-staircases," which are initialized at 60% contrast with steps of .05 log units and employs a 3/1 staircase that after every 40 trials is reset (the "short" in "short-staircases") back to 60% contrast.
C4 - Mixed Difficulty (MD)
BehavioralThis condition will be identical to SPL with the exception that two staircases - one a 2/1 staircase producing difficulties centered around 60-70% accuracy, the other a 4/1 staircase producing difficulties centered around 85-95% accuracy - will be utilized to control the stimuli.
C5 - Noise Training (NT)
BehavioralThe NT condition will be the same as SPL with the exception that contrast thresholds will be estimated in 5-different levels of external noise (10%, 15%, 20%, 25%, 30%).
C6 - Training with Flankers (TWF)
BehavioralTWF will be reasonably different from the standard SPL task. Here, on 50% of trials a target Gabor will be presented at either 45° or 135° (as in SPL) and will be flanked by two collinear Gabors. On the remaining 50% of trials, flankers will be present without a target. TWF is thus a yes/no detection task, which is necessary since the collinear flankers fully indicate the target orientation. In different 20-trial mini-blocks the flankers will appear either lambda, 1.5 lambda, or 2 lambda from the target (i.e., closer or further from the target) and target contrast will be controlled by a 3/1 staircase separately for each spacing.
C7 - Parafoveal Training (PT)
BehavioralThe PT condition is the baseline for C8-C11 (all of which involve parafoveally presented targets). In PT, we utilize the same task as in SPL, however, in PT, in addition to central training, targets will also appear in one of two peripheral locations (5° eccentricity; angles = 135° and 270°). The location of targets will be randomized trial-wise so as to discourage eye-movements and independent 3/1 staircases will be run at each location. By training only 2 peripheral locations we can measure the extent to which training gives rise to location transfer (e.g., in transfer tasks examining performance at 8 different locations - 2 trained locations and 6 untrained locations). Furthermore, training at the central location facilitates comparisons between PT and SPL.
C8 - Stimulus Variety (SV)
BehavioralThe base task for SV is the PT condition. However, SV employ 20 trial mini-blocks of different SFs (.75, 1.5, 3, 6, 12, 24 cpd) and locations (45°, 135°, 225°, 315° - i.e., more locations than PT, but not the full set tested in the transfer battery) with separate staircases for each SF and location. Orientations will also be drawn from a larger set (22.5°, 45°, 67.5° - for which participants respond "clockwise" and 112.5°, 135°, 157.5° - for which participants respond "counter-clockwise") and will vary on a trial-by-trial basis. This design holds-out 4 locations and 2 orientations to address transfer.
C8a - Complex Features (CF)
BehavioralThis is the same as C8, however we will use band-pass filtered stimuli similar to what has been done by a number of groups including Hussein et al.
C9 - Exogenous Attention Training (ExAT)
BehavioralStimuli will be presented in a similar manner as in PT. However, in ExAT, a 100% valid cue, a small black dot - 48ms duration with an 96ms SOA prior to stimulus onset - will appear above the target location on each trial.
C10 - Endogenous Attention Training (EnAT)
BehavioralStimuli will be presented in a similar manner as in PT. However, in EnAT, a 100% valid cue (letter UL, LR; standing for upper left and lower right, respectively) - 150ms duration with an 500ms SOA prior to stimulus onset - will appear at the fixation point.
C11 - Multisensory Facilitation (MF)
BehavioralMF utilizes the same basic task structure as in ExEAT, however, rather than a visual cue, an auditory cue will be used (50ms, 1000hz tone with sound location determined by convolving sound with generic head-related transfer function, kemar large ears.
No Contact Control
BehavioralWhile not a "training condition" one type of experience that could be part of a condition is a no contact control (i.e., where participants do no training activities over the same rough time span as for the other training tasks).
Treatment groups
1,140 Participants
are divided into 18 treatment groups18
Treatment groupsSee each treatment group below.
Group A: C1 - Standard Perceptual Learning (SPL)Experimental treatment 7 interventions
Group B: C2 - Long Training (LT)Experimental treatment 3 interventions
Group C: C3 - Short Staircases (SS)Experimental treatment 3 interventions
Group D: C4 - Mixed Difficulty (MD)Experimental treatment 3 interventions
Group E: C5 - Noise Training (NT)Experimental treatment 3 interventions
Group F: C6 - Training with Flankers (TWFExperimental treatment 3 interventions
Group G: C7 - Parafoveal Training (PT)Experimental treatment 7 interventions
Group H: C8 - Stimulus Variety (SV)Experimental treatment 3 interventions
Group I: C8a - Complex Features (CF)Experimental treatment 3 interventions
Group J: C9 - Exogenous Attention Training (ExAT)Experimental treatment 3 interventions
Group K: C10 - Endogenous Attention Training (EnAT)Experimental treatment 3 interventions
Group L: C11 - Multisensory Facilitation (MF)Experimental treatment 3 interventions
Group M: No Contact ControlOther 13 interventions
Group N: OA1 - Standard Perceptual LearningExperimental treatment 1 intervention
Group O: OA2 - Noise TrainingExperimental treatment 1 intervention
Group P: OA3 - Training with FlankersExperimental treatment 1 intervention
Group Q: OA4 - Stimulus VarietyExperimental treatment 1 intervention
Group R: OA5 - No Contact ControlExperimental treatment 1 intervention
Trial outcomes
Primary outcomes
1
Change in Near Transfer Task
We will utilize an overarching task structure that allows us to assess learning on trained stimuli and transfer to untrained stimuli; locations, orientations, stimulus timings (e.g., we will assess contrast sensitivity for 6 different orientations). A trial begins with a fixation-point presented for 500ms. A target stimulus then appears for 128ms and then disappears (this timing was chosen to preclude participants making eye-movements to the stimuli). The participant is then required to respond by indicating the orientation of the stimulus (e.g., the major axis of a Gabor stimulus or gap-side of a C stimulus). In contrast tests, a staircase is run on the contrast of the target stimulus. In acuity tests, a staircase is run on the size of the stimulus. In parafoveal tests, stimuli are presented at 5° eccentricity.
Time frame
Baseline to Post-test 2, an average of 5-8 weeks2
Change in Transfer to Visual Search
In a T/L annular visual-search task (1° stimuli, presented at 5° eccentricity at each of 8 evenly spaced locations), on each trial, 7 positions are filled with a distractor (upside-down Ls, half black and half white), while 1 position contains a target (rightside-up T that is either white or black). Stimuli are presented for 256ms and, after a variable SOA, a stimulus-mask (asterixis) appears. Participants report the color of the T. A 3/1 staircase controls the SOA of the mask (shorter SOAs = less time between stimulus and mask = more difficult). This task tests how training impacts processing time (i.e., time necessary to find and identify targets). Also, given that the same locations are used as in the parafoveal training, we can also estimate the extent to which transfer to visual search occurs and, if so, whether it is specific to the trained location.
Time frame
Baseline to Post-test 2, an average of 5-8 weeks3
Change in Transfer to Reading
To understand visual performance related to reading, we employ the MNRead task, where participants read short sentences out-loud at various font-sizes. Dependent variables include reading speed, minimal text-size (another measure of acuity), and also critical print-size (text-size at which reading speed slows down).
Time frame
Baseline to Post-test 2, an average of 5-8 weeks4
Change in Transfer to Auditory Attention
The procedure is based upon a speaker-on-speaker task where participants choose between 36 call signs (a color and number) spoken by a speaker. This task measures auditory thresholds for speech in the presence of other talkers, when all talkers are spatially collocated compared to when they are spatially offset.
Time frame
Baseline to Post-test 2, an average of 5-8 weeksSponsors and contacts
Click on the lead sponsor to view all of their trials.
University of Wisconsin, Madison
Lead sponsor
National Eye Institute (NEI)
Collaborator
Source ClinicalTrials.gov