Effects of long-time reading experience on reaction time and the recognition potential

Abstract

The proposition that long-time experience in reading a language gradually builds up rapidly acting neural processes that facilitate the processing of words in that language and speed them into conscious awareness was examined. Behavioral reaction time (RT) and electrophysiological responsiveness to visually displayed words and non-language images were measured in persons who differed in how much experience they had in reading English. The electrophysiological response was the recognition potential (RP). Behavioral RT and the latency of the RP to English words were both expected to depend upon how much English reading experience a person had. The short latency of the RP was expected to free it from the influence of non-perceptual factors that affect RT, such as speed/accuracy tradeoff. This expectation yielded the prediction that the behavioral and electrophysiological results would differ in a specific way. Long-time readers of English were expected to show shorter RP latency to English words than less experienced (China-educated) readers of English but no RP latency difference for non-language images, with which neither group had greater experience. In contrast, due to speed accuracy tradeoff, the China-educated subjects were expected to show longer RT for both the words and the non-language images. The prediction was confirmed. The amount of language experience that a person had showed a stronger relationship to RP latency than it did to RT. This helped to validate the use of the RP as a tool for investigating perception and demonstrated definite advantages that it has for studying acquired perceptual processes in humans.

Fig. 1

Background and target images. The array of images at the top (A) contains 14 background images, one Gestalt figure target, and one English word target. The middle array (B) contains the 16 word targets. The bottom array (C) contains the 16 Gestalt targets. The images are black on white in this figure, but they were white on black when displayed on the computer monitor.

Fig. 2

Monopolar recordings and derived waveforms. The electrical responses shown in this figure are grand averages computed for all Word and Gestalt target stimuli and all subjects. Monopolar average waveforms recorded from electrodes placed at Fz, Cz, Pz, Oz, and Sub-Oz locations are shown at the top of the figure. An electrode on the right ear lobe served as a common reference. The bottom of the figure shows two waveforms that were derived from the monopolar recordings. A bipolar waveform was obtained by calculating the Pz – Oz difference. Neither electrode site was assumed to be inactive. The RP, as measured in previous studies, is the initial downward deflection of the Pz – Oz waveform. It indicates that the Oz electrode is becoming more positive relative to the Pz electrode or equivalently that the Pz electrode is becoming more negative relative to the Oz electrode. The other derivation was a composite waveform that was calculated from the five monopolar recordings, applying specified weights to each. The composite derivation was used for data analyses and for plotting waveforms in other figures. The 2 μV calibration marker applies to all waveforms in the figure.

Fig. 3

The RT histogram and the grand average recognition potential computed for all Word and Gestalt target trials and all subjects. The vertical lines at time zero indicate the onset of a 200 ms duration target image. The time window used to define a correct behavioral response and the time window used for measuring the RP are indicated.

Fig. 4

The recognition potential for USA-Educated readers of English. The line passing through the most positive value of the word target average waveform and the most positive value of the Gestalt target average waveform indicates that in these subjects RP latency was slightly less for English words than it was for Gestalt figures.

Fig. 5

The recognition potential for China-Educated readers of English. The line passing through the most positive value of the word target average waveform and the most positive value of the Gestalt target average waveform indicates that in these subjects RP latency was substantially longer for English words than it was for Gestalt figures.

Fig. 6

Behavioral reaction time versus recognition potential latency. The error bars indicate one standard error of the mean.