Data from: A robust and representative lower bound on object processing speed in humans

How early does the brain decode object categories? Addressing this
question is critical to constrain the type of neuronal architecture
supporting object categorization. In this context, much effort has been
devoted to estimating face processing speed. With onsets estimated from 50
to 150 ms, the timing of the first face-sensitive responses in humans
remains controversial. This controversy is due partially to the
susceptibility of dynamic brain measurements to filtering distortions and
analysis issues. Here, using distributions of single-trial event-related
potentials (ERPs), causal filtering, statistical analyses at all
electrodes and time points, and effective correction for multiple
comparisons, we present evidence that the earliest categorical differences
start around 90 ms following stimulus presentation. These results were
obtained from a representative group of 120 participants, aged 18-81, who
categorized images of faces and noise textures. The results were reliable
across testing days, as determined by test-retest assessment in 74 of the
participants. Furthermore, a control experiment showed similar ERP onsets
for contrasts involving images of houses or white noise. Face onsets did
not change with age, suggesting that face sensitivity occurs within 100 ms
across the adult lifespan. Finally, the simplicity of the face-texture
contrast, and the dominant midline distribution of the effects, suggest
the face responses were evoked by relatively simple image properties and
are not face specific. Our results provide a new lower benchmark for the
earliest neuronal responses to complex objects in the human visual system.