The encoding of temporally irregular and regular visual patterns in the human brain reports a functional magnetic resonance imaging study where subjects viewed temporal sequence that were either regular or irregular.
The sequences consisted of letters, number, colors and luminances.
 Abstract for CC-by article
In the work reported here, we set out to study the neural systems that detect predictable temporal patterns and departures from them. We used functional magnetic resonance imaging (fMRI) to locate activity in the brains of subjects when they viewed temporally regular and irregular patterns produced by letters, numbers, colors and luminance. Activity induced by irregular sequences was located within dorsolateral prefrontal cortex, including an area that was responsive to irregular patterns regardless of the type of visual stimuli producing them. Conversely, temporally regular arrangements resulted in activity in the right frontal lobe (medial frontal gyrus), in the left orbito-frontal cortex and in the left pallidum. The results show that there is an abstractive system in the brain for detecting temporal irregularity, regardless of the source producing it.
Group 1 of 16 right-handed healthy volunteers with 9 males and 7 females were included in the study.
The group had a mean age of 28.
The study on the human subjects was approved by the Ethics Committee of the National Hospital for Neurology and Neurosurgery.
|MRI Scanning (help)
(TR=3420ms, TE=90ms, FA=?)
||38 (thickness=2mm , gap=1mm)
|| matrix=64 x 64
For fMRI EPI scans were acquired with a Siemens Sonata.
A T1-weighted scanning was also made.
Brain scans were analyzed with SPM2 with spatial normalization to MNI space and the statistical threshold set on P<0.001 uncorrect for multiple comparison.
 Numbers versus others
1 coordinate mentioned in text
 Letters versus others
1 coordinate mentioned in text.
 Luminance versus others
2 coordinates mentioned in text.
 Color versus others
One coordinate in the text in the "A. The effects of temporal sequences on activity in specialized visual areas" section.
It is stated that the activation was bilateral, but no coordinate is given in the left hemisphere. Though the coordinate given in has a minus sign for the x-coordinate!?
 Irregularity versus regularity
It is stated that the there was "broad activity in the dorsolateral frontal cortex, corresponding to, but extending beyond, Brodmann Area 46 (p<0.001 uncorrected) into Brodmann areas 9, 45 and 44." but no coordinate is given for that area
 Regularity versus irregularity
3 coordinates mentioned in text.
 Irregularity versus regularity (conjunction analysis)
1 coordinate mention in text.