Stimulus, task, and learning effects on measures of temporal resolution: implications for predictors of language outcome.
OBJECTIVE
Some studies find that temporal processing ability predicts language outcome whereas other studies do not. Resolution of this debate is hindered by the variety of temporal measures used, nonsensory loading of the tasks, and differential amounts of practice across studies. The goal of this study was to examine the effects of stimulus properties, experimental task, and perceptual learning on listeners' gap detection performance.


METHODS
Gap detection thresholds were obtained from adults with normal hearing and language ability. The effects of marker frequency similarity and marker duration on thresholds were examined in yes-no, two-interval forced-choice (2IFC), and dual-pair comparison tasks (which vary in nonsensory loading) over 4 days of testing.


RESULTS
Thresholds were highest for gaps defined by markers with disparate frequencies (1000 and 4000 Hz; i.e., between-channel gap detection), and with longer (300 ms) trailing markers, obtained using yes-no and 2IFC tasks. However, these effects were attenuated with training or the initial use of the dual-pair comparison task.


CONCLUSIONS
These results suggest that gap detection thresholds reflect a variety of sensory and nonsensory factors. Understanding these underlying factors is critical to any evaluation of the relation between temporal processing and language outcome.
Smith
Nicholas A
NA
Department of Psychology, Neuroscience and Behaviour, McMaster University, 1280 Main Street West, Hamilton, Ontario L8S 4K1, Canada.
Trainor
Laurel J
LJ
Gray
Kellie
K
Plantinga
Judy A
JA
Shore
David I
DI
D000293:Adolescent; D001309:Auditory Threshold; D005260:Female; D006801:Humans; D007802:Language; D007858:Learning; D008297:Male; D010470:Perceptual Masking; D013067:Speech Perception; D013998:Time Perception; D014706:Verbal Learning; D055815:Young Adult