Reading the mind's eye: Online detection of visuo-spatial working memory and visual imagery in the inferior temporal lobe
| Autor: | Sarang S. Dalal, Tomás Ossandón, Jean-Philippe Lachaux, Karim Jerbi, Lorella Minotti, Carlos M. Hamamé, Olivier F. Bertrand, Philippe Kahane, Juan R. Vidal |
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| Rok vydání: | 2012 |
| Předmět: |
Adolescent
genetic structures Cognitive Neuroscience behavioral disciplines and activities Spatial memory 050105 experimental psychology 03 medical and health sciences 0302 clinical medicine Visual memory Inferior temporal gyrus Humans 0501 psychology and cognitive sciences Visual short-term memory Recognition memory Brain Mapping Working memory 05 social sciences Electroencephalography Iconic memory Temporal Lobe Memory Short-Term Neurology Imagination Visual Perception Female Verbal memory Psychology 030217 neurology & neurosurgery Cognitive psychology |
| Zdroj: | NeuroImage; Vol 59 |
| ISSN: | 1053-8119 |
| DOI: | 10.1016/j.neuroimage.2011.07.087 |
| Popis: | Several brain regions involved in visual perception have been shown to also participate in non-sensory cognitive processes of visual representations. Here we studied the role of ventral visual pathway areas in visual imagery and working memory. We analyzed intracerebral EEG recordings from the left inferior temporal lobe of an epileptic patient during working memory tasks and mental imagery. We found that high frequency gamma-band activity (50–150 Hz) in the inferior temporal gyrus (ITG) increased with memory load only during visuo-spatial, but not verbal, working memory. Using a real-time set-up to measure and visualize gamma-band activity online – BrainTV – we found a systematic activity increase in ITG when the patient was visualizing a letter (visual imagery), but not during perception of letters. In contrast, only 7 mm more medially, neurons located in the fusiform gyrus exhibited a complete opposite pattern, responding during verbal working memory retention and letter presentation, but not during imagery or visuo-spatial working memory maintenance. Talairach coordinates indicate that the fusiform contact site corresponds to the word form area, suggesting that this region has a role not only in processing letter-strings, but also in working memory retention of verbal information. We conclude that neural networks supporting imagination of a visual element are not necessarily the same as those underlying perception of that element. Additionally, we present evidence that gamma-band activity in the inferior temporal lobe, can be used as a direct measure of the efficiency of top-down attentional control over visual areas with implications for the development of novel brain-computer interfaces. Finally, by just reading gamma-band activity in these two recording sites, it is possible to determine, accurately and in real-time, whether a given memory content is verbal or visuo-spatial. |
| Databáze: | OpenAIRE |
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