Comparing single-unit recordings taken from a localist model to single-cell recording data: a good match** The underlying research materials for this article can be accessed at http://adelmanlab.org/easyNet/downloads/Shunted-SCM_files/View all notes

Single-cell recording studies show that some neurons respond to complex visual information (e.g. words, objects, faces) in a highly selective manner, with individual neurons responding to about 0.5% of presented images. Such data have often been taken as inconsistent with “grandmother cell” theories as well as with localist models in psychology. In particular, it is commonly assumed that units in localist models respond to only one input, resulting in greater levels of selectivity than seen in single-cell results. To test this assumption, we recorded unit activity from a localist model of word identification. Our results show that the model can capture the levels of selectivity reported in neuroscience. Accordingly, single-cell data do not rule out localist coding schemes. We propose that the term grandmother cell should be reserved for the hypothesis that the brain implements localist representations: neurons that represent one and only one thing but respond to multiple things.