A single-neuron correlate of change detection and change blindness in the human medial temporal lobe.
Observers are often unaware of changes in their visual environment when attention is not focused at the location of the change . Because of its rather intriguing nature, this phenomenon, known as change blindness, has been extensively studied with psychophysics as well as with fMRI . However, whether change blindness can be tracked in the activity of single cells is not clear. To explore the neural correlates of change detection and change blindness, we recorded from single neurons in the human medial temporal lobe (MTL) during a change-detection paradigm. The preferred pictures of the visually responsive units elicited significantly higher firing rates on the attended trials when subjects correctly identified a change (change detection) compared to the unattended trials when they missed it (change blindness). On correct trials, the firing activity of individual units allowed us to predict the occurrence of a change, on a trial-by-trial basis, with 67% accuracy. In contrast, this prediction was at chance for incorrect, unattended trials. The firing rates of visually selective MTL cells thus constitute a neural correlate of change detection.
Reddy
Leila
L
Computation and Neural Systems, California Institute of Technology, Pasadena, California 91125, USA. lreddy@klab.caltech.edu
Quiroga
Rodrigo Quian
RQ
Wilken
Patrick
P
Koch
Christof
C
Fried
Itzhak
I
D000200:Action Potentials / Q000502:physiology; D000328:Adult; D004567:Electrodes, Implanted; D005260:Female; D005364:Field Dependence-Independence; D006801:Humans; D007395:Interneurons / Q000502:physiology*; D008297:Male; D010364:Pattern Recognition, Visual / Q000502:physiology*; D010775:Photic Stimulation; D012372:ROC Curve; D013702:Temporal Lobe / Q000166:cytology / Q000502:physiology*