On sense and senses: Intelligence and auditory information processing

Abstract

Brighter people process information faster than the less bright on a variety of cognitive tasks, but interpretation of this observation is ambiguous. The first two experiments here emphasize discrimination ability while downplaying speed-of-processing, yet indicate significant aptitude-related differences. Both experiments involve frequency discrimination of two 20-msec tones in the absence of any masking using a two-interval forced choice procedure. Correlations of frequency discrimination thresholds with Cattell's Culture Fair Intelligence Test IQ in college students range between -0.42 and -0.54. Placing more emphasis on resolution than speed, the results suggest that higher intelligence may be associated with greater resolution capacity, which in turn may increase speed of performance. The third experiment tested the hypothesis that brighter people perform better on any novel ‘nonentrenched’ task. Brief tone bursts were embedded in broadband noise, in notched noise (distracting, but containing no frequencies near the fundamental of the target tone), or in quiet. No aptitude-related differences in signal detection thresholds were observed, suggesting that aptitude-related effects of novelty per se are an unlikely explanation for the superior frequency discrimination performance of brighter college students. Detection tasks, in contrast to recognition tasks, do not tap the ‘higher’ cognitive functions associated with psychometric intelligence.